- UIA
- UIA Praga 1967 [Známka 1622] [Stamp 1622]
- UIT
- UIT [Známka 2581] [Stamp 2581]
- ULD
- ULD Prague 1960 [Známka 1192] [Stamp 1192]
- UN
- 20th Anniversary of the Signing of the UN Charter [Známka 1454] [Stamp 1454]
- 20 Years of the UN [Známka 1455] [Stamp 1455]
- UN - 25 Years [Známka 1833] [Stamp 1833]
- UN 35 Years [Známka 2442] [Stamp 2442]
- 2nd Special Session of the UN General Assembly on Disarmament, New York 1982 [Známka 2541] [Stamp 2541]
- 2nd UN Conference on the Exploration and Peaceful Uses of Outer Space [Aršik 2544] [Souvenir Sheet 2544]
- UNECEF
- UNECEF 1946-1986 [Známka 2750] [Stamp 2750]
- UNECEF 1946-1986 [Známka 2751] [Stamp 2751]
- UNECEF 1946-1986 [Známka 2752] [Stamp 2752]
- UNECEF 1946-1986 [Známka 2753] [Stamp 2753]
- UNECEF 1946-1986 [Známka 2754] [Stamp 2754]
- UNESCO
- UNESCO Friendship for the Children of the World Contest [Známka 1023] [Stamp 1023]
- UNESCO Peace Contest [Známka 1024] [Stamp 1024]
- UNESCO We Want to Live with Peace and Joy Contest [Známka 1025] [Stamp 1025]
- UNESCO [Známka 1331] [Stamp 1331]
- UNESCO [Známka 1332] [Stamp 1332]
- UNESCO [Známka 1333] [Stamp 1333]
- UNESCO [Známka 1334] [Stamp 1334]
- UNESCO [Známka 1335] [Stamp 1335]
- UNESCO [Známka 1336] [Stamp 1336]
- UNESCO [Známka 1365] [Stamp 1365]
- UNESCO [Známka 1366] [Stamp 1366]
- UNESCO [Známka 1367] [Stamp 1367]
- UNESCO [Známka 1368] [Stamp 1368]
- UNESCO R. Rolland 1860-1944 [Známka 1504] [Stamp 1504]
- 20 Years of UNESCO 1946-1966 [Známka 1515] [Stamp 1515]
- Petr Bezruc 1867-1967 UNESCO [Známka 1623] [Stamp 1623]
- Karel Marx 1818 UNESCO [Známka 1664] [Stamp 1664]
- Czechosloval UNESCO Commission [Známka 1722] [Stamp 1722]
- Czechosloval UNESCO Commission [Známka 1723] [Stamp 1723]
- Czechosloval UNESCO Commission [Známka 1724] [Stamp 1724]
- Czechosloval UNESCO Commission [Známka 1725] [Stamp 1725]
- Czechosloval UNESCO Commission [Známka 1726] [Stamp 1726]
- Czechosloval UNESCO Commission [Známka 1727] [Stamp 1727]
- Czechosloval UNESCO Commission [Známka 1728] [Stamp 1728]
- Czechosloval UNESCO Commission [Známka 1768] [Stamp 1768]
- Czechosloval UNESCO Commission [Známka 1769] [Stamp 1769]
- Czechosloval UNESCO Commission [Známka 1770] [Stamp 1770]
- Czechosloval UNESCO Commission [Známka 1771] [Stamp 1771]
- Czechosloval UNESCO Commission [Známka 1772] [Stamp 1772]
- Czechosloval UNESCO Commission [Známka 1773] [Stamp 1773]
- UNESCO [Známka 1810] [Stamp 1810]
- UNESCO [Známka 1811] [Stamp 1811]
- UNESCO [Známka 1812] [Stamp 1812]
- UNESCO [Známka 1813] [Stamp 1813]
- UNESCO [Známka 1814] [Stamp 1814]
- UNESCO [Známka 1815] [Stamp 1815]
- UNESCO [Známka 1884] [Stamp 1884]
- UNESCO [Známka 1885] [Stamp 1885]
- UNESCO International Year of the Book 1972 [Známka 1946] [Stamp 1946]
- UNESCO [Známka 2077] [Stamp 2077]
- UNESCO [Známka 2078] [Stamp 2078]
- UNESCO [Známka 2079] [Stamp 2079]
- UNESCO [Známka 2080] [Stamp 2080]
- UNESCO [Známka 2081] [Stamp 2081]
- UNESCO [Známka 2182] [Stamp 2182]
- UNESCO [Známka 2183] [Stamp 2183]
- UNESCO [Známka 2184] [Stamp 2184]
- UNESCO 1946-1976 [Známka 2211] [Stamp 2211]
- UNESCO [Známka 2292] [Stamp 2292]
- Man and the Biosphere UNESCO [Známka 2383] [Stamp 2383]
- Man and the Biosphere UNESCO [Přepážkovy list 2383] [Minisheet 2383]
- Man and the Biosphere UNESCO [Známka 2384] [Stamp 2384]
- Man and the Biosphere UNESCO [Přepážkovy list 2384] [Minisheet 2384]
- Man and the Biosphere UNESCO [Známka 2385] [Stamp 2385]
- Man and the Biosphere UNESCO [Přepážkovy list 2385] [Minisheet 2385]
- Man and the Biosphere UNESCO [Známka 2386] [Stamp 2386]
- Man and the Biosphere UNESCO [Přepážkovy list 2386] [Minisheet 2386]
- UNESCO [Kupon 2388] [Coupon 2388]
- UNESCO [Kupon 2389] [Coupon 2389]
- UNESCO [Kupon 2390] [Coupon 2390]
- UNESCO [Kupon 2391] [Coupon 2391]
- UNESCO [Kupon 2392] [Coupon 2392]
- UNESCO [Známka 2475] [Stamp 2475]
- UNESCO [Známka 2480] [Stamp 2480]
- 100th Birth Anniversary - UNESCO [Známka 2514] [Stamp 2514]
- 100th Birth Anniversary - UNESCO [Známka 2516] [Stamp 2516]
- (100th Birth Anniversary - UNESCO) [Známka 2517] [Stamp 2517]
- 10th International Exhibition of Children's Art Lidice (UNESCO) [Známka 2538 1. vydání] [Stamp 2538 1st Issue]
- 10th International Exhibition of Children's Art Lidice UNESCO [Aršik 2538 1. vydání] [Souvenir Sheet 2538 1st Issue]
- 10th International Exhibition of Children's Art Lidice (UNESCO) [Známka 2538 2. vydání] [Stamp 2538 2nd Issue]
- 10th International Exhibition of Children's Art Lidice UNESCO [Aršik 2538 2. vydání] [Souvenir Sheet 2538 2nd Issue]
- (100th Birth Anniversary - UNESCO) [Známka 2542] [Stamp 2542]
- UNESCO [Známka 2575] [Stamp 2575]
- UNESCO [Známka 2577] [Stamp 2577]
- UNESCO [Známka 2613] [Stamp 2613]
- UNESCO [Aršik 2613] [Souvenir Sheet 2613]
- (200th Birth Anniversary - UNESCO) [Známka 2676] [Stamp 2676]
- UNESCO [Známka 2678] [Stamp 2678]
- (100th Birth Anniversary - UNESCO) [Známka 2726] [Stamp 2726]
- (100th Birth Anniversary - UNESCO) [Známka 2772] [Stamp 2772]
- (100th Birth Anniversary - UNESCO) [Známka 2772] [Stamp 2772]
- Jan Evangelista Purkyne - 1787-1987 - UNESCO [Známka 2811] [Stamp 2811]
- 100th Birth Anniversary - UNESCO [Známka 2820] [Stamp 2820]
- 100th Birth Anniversary - UNESCO [Známka 2821] [Stamp 2821]
- UNESCO [Známka 2863] [Stamp 2863]
- (100th Birth Anniversary - UNESCO) [Známka 2870] [Stamp 2870]
- UNESCO [Známka 2883] [Stamp 2883]
- UNESCO 1990 [Kupon 2921] [Coupon 2921]
- UNESCO [Známka 2922] [Stamp 2922]
- UNESCO [Známka 2926] [Stamp 2926]
- UNESCO [Známka 2927] [Stamp 2927]
- UNESCO - 100th Birth Anniversary [Známka 2961] [Stamp 2961]
- UNESCO [Známka 3002] [Stamp 3002]
- UNESCO [Známka 7] [Stamp 7]
- UNESCO [Známka 14] [Stamp 14]
- UNESCO [Známka 18] [Stamp 18]
- UNESCO [Známka 32] [Stamp 32]
- UNESCO [Známka 33] [Stamp 33]
- UNESCO [Známka 39] [Stamp 39]
- UNESCO [Známka 66] [Stamp 66]
- UNESCO [Známka 119] [Stamp 119]
- 1946 UNESCO 1996 [Přepážkovy list 119] [Minisheet 119]
- UNESCO [Aršik 141] [Souvenir Sheet 141]
- UNESCO [Známka 174] [Stamp 174]
- UNESCO [Známka 186] [Stamp 186]
- UNESCO [Známka 193] [Stamp 193]
- UNESCO [Známka 194] [Stamp 194]
- UNESCO [Známka 226] [Stamp 226]
- UNESCO [Známka 247] [Stamp 247]
- UNESCO [Známka 304] [Stamp 304]
- UNESCO [Známka 305] [Stamp 305]
- UNESCO [Známka 333] [Stamp 333]
- UNESCO [Známka 334] [Stamp 334]
- UNESCO [Známka 429] [Stamp 429]
- UNESCO [Známka 430] [Stamp 430]
- UNESCO Biosphere Reserve [Aršik 525] [Souvenir Sheet 525]
- UNESCO Biosphere Reserve [Aršik 563] [Souvenir Sheet 563]
- UNESCO Biosphere Reserve [Aršik 604] [Souvenir Sheet 604]
- Lower Moravian UNESCO Biosphere Preserve [Aršik 645] [Souvenir Sheet 645]
- UNESCO Biosphere Reserve [Aršik 691] [Souvenir Sheet 691]
- UNESCO - 70 years [Známka 909] [Stamp 909]
- UNICEF
- UNICEF 1946-1971 [Známka 1927] [Stamp 1927]
- UNICEF 1946-1971 [Známka 1928] [Stamp 1928]
- UNICEF 1946-1971 [Známka 1929] [Stamp 1929]
- UNICEF 1946-1971 [Známka 1930] [Stamp 1930]
- UNICEF 1946-1971 [Známka 1931] [Stamp 1931]
- UNICEF 1946-1971 [Známka 1932] [Stamp 1932]
- UNICEF 1946-1996 [Známka 121] [Stamp 121]
- UPU
- UPU 1874 1949 [Známka 508] [Stamp 508]
- UPU 1874 1949 [Známka 509] [Stamp 509]
- UPU 1874 1949 [Známka 510] [Stamp 510]
- US
- US enters the war against Germany [Aršik 947] [Souvenir Sheet 947]
- USA
- Meteorological Cooperation between the USSR and USA [Známka 1427] [Stamp 1427]
- Derringer, USA, circa 1865 [Známka 1749] [Stamp 1749]
- USSR - USA [Známka 2164] [Stamp 2164]
- Susan Jeffers - USA [Aršik 2600] [Souvenir Sheet 2600]
- Erick Ingraham (USA) [Známka 2712] [Stamp 2712]
- World Championship Soccer USA 1994 [Známka 45] [Stamp 45]
- USSR
- USSR [Známka 1069] [Stamp 1069]
- USSR Wins in Space 4-12-1961 [Známka 1178] [Stamp 1178]
- 40th Anniversary of the USSR [Známka 1272] [Stamp 1272]
- 40 Years of the USSR [Známka 1273] [Stamp 1273]
- 20th Anniversary of the Friendship and Mutual Assistance Treaty between
Czechsoslovakia and the USSR 1943-1963 [Známka 1344] [Stamp 1344]
- 20th Anniversary of the Friendship and Mutual Assistance Treaty between
Czechsoslovakia and the USSR 1943-1963 [Známka 1345] [Stamp 1345]
- Meteorological Cooperation between the USSR and USA [Známka 1427] [Stamp 1427]
- 1st Czechoskovak Battalion in the USSR [Známka 1945] [Stamp 1945]
- 50th Anniversary of the USSR 1922-1972 [Známka 1992] [Stamp 1992]
- Czechoslovakia - USSR [Známka 2138] [Stamp 2138]
- USSR - Czechoslovakia - DDR [Známka 2160] [Stamp 2160]
- USSR - France [Známka 2161] [Stamp 2161]
- USSR - India [Známka 2162] [Stamp 2162]
- USSR - Poland [Známka 2163] [Stamp 2163]
- USSR - USA [Známka 2164] [Stamp 2164]
- Salyut - USSR [Známka 2280] [Stamp 2280]
- 55th Anniversary of the USSR 1922-1917 [Známka 2282] [Stamp 2282]
- Joint USSR -Czechoslovak Flight [Známka 2296] [Stamp 2296]
- Joint USSR -Czechoslovak Flight [Známka 2297] [Stamp 2297]
- Joint Czechoslovak-USSR Flight [Známka 2362] [Stamp 2362]
- 50th Anniversary of the USSR 1922-1982 [Známka 2562] [Stamp 2562]
- 5th Anniversary of the Joint USSR-Czechoslovak Flight 1978-1983 [Známka 2586] [Stamp 2586]
- Joint USSR-Czechoslovak Flight [Známka 2586] [Stamp 2586]
- Uher
- Milos Uher [Známka 2072] [Stamp 2072]
- Uherske
- Uherske Hradiste 1257-1957 [Známka 923] [Stamp 923]
- Uherske Hradiste [Známka 1789] [Stamp 1789]
- Uhersky
- Uhersky Brod [Známka 1889] [Stamp 1889]
- Ukraine
- Carpatho-Ukraine [Známka 351] [Stamp 351]
- Carpatho-Ukraine [Známka 351 2. vydání] [Stamp 351 2nd Issue]
- Carpatho-Ukraine [Známka N351] [Stamp N351]
- Carpatho-Ukraine [Známka N351] [Stamp N351]
- Ukrainian
- [Ukrainian Philatelic and Numismayic Society. Glenspey, New York] [Známka N351] [Stamp N351]
- [Ukrainian Philatelic and Numismayic Society. Glenspey, New York] [Známka N351] [Stamp N351]
- Ukrainpex
- [Label. Ukrainpex 1984. Roman J. Mudry] [Známka N351] [Stamp N351]
- [Label. Ukrainpex 1984. Roman J. Mudry] [Známka N351] [Stamp N351]
- Ulf
- Ulf Lofgren [Sweden] [Známka 2269] [Stamp 2269]
- Under
- Socialism Built Under the Leadership of the Czechoslovak Communist Party [Známka 994] [Stamp 994]
- Under Socialism for Peace [Známka 1115] [Stamp 1115]
- Underwing
- Union
- 2nd Trade Union Congress 1949 [Známka 525] [Stamp 525]
- 2nd Trade Union Congress 1949 [Známka 526] [Stamp 526]
- With the Soviet Union for Peace and Socialism [Známka 569] [Stamp 569]
- With the Soviet Union for Peace and Socialism [Známka 570] [Stamp 570]
- With the Soviet Union Forever [Známka 590] [Stamp 590]
- Building Socialism in our Country with the Soviet Union [Známka 802] [Stamp 802]
- Building Socialism in our Country with the Soviet Union [Známka 803] [Stamp 803]
- Building Socialism in our Country with the Soviet Union [Známka 804] [Stamp 804]
- 3rd World Trade Union Congress [Známka 827] [Stamp 827]
- 3rd World Trade Union Congress [Známka 828] [Stamp 828]
- 4th World Trade Union Congress, October 1957 Leipzig [Známka 960] [Stamp 960]
- 1st World Trade Union Conference of Working Youth, Prague 1958 [Známka 997] [Stamp 997]
- 4th Trade Union Congress, Prague May 1959 [Známka 1054] [Stamp 1054]
- 4th Trade Union Congress 1959 [Známka 1055] [Stamp 1055]
- 5th World Trade Union Congress Moscow 12-1-1961 12-16-1961 [Známka 1226] [Stamp 1226]
- 100th Anniversary of the Union of Czechoslovak Mathematics and Physics [Známka 1236] [Stamp 1236]
- 100th Anniversary of the Union of Czechoslovak Mathematics and Physics [Známka 1239] [Stamp 1239]
- 5th Trade Union Congress - Prague [Známka 1293] [Stamp 1293]
- 4th Czechoslovak Youth Union Congress, Prague 1963 [Známka 1301] [Stamp 1301]
- 20 Years of the World Trade Union Federation [Známka 1457] [Stamp 1457]
- ITU International Telecomunication Union 1865-1965 [Známka 1465] [Stamp 1465]
- 5th Congress of the Czechoslovak Youth Union [Známka 1580] [Stamp 1580]
- 6th Trade Union Congress, Prague [Známka 1581] [Stamp 1581]
- 9th Congress of the International Union of Architects [Známka 1622] [Stamp 1622]
- 16th Universal postal Union Congress, Tokyo 1969 [Známka 1791] [Stamp 1791]
- Socialist Youth Union [Známka 1852] [Stamp 1852]
- Federations of Workers' Union Physical Exercise 1921-1971 [Známka 1910] [Stamp 1910]
- 3rd World Trade Union Congress 1972 [Známka 1963] [Stamp 1963]
- 8th World Trade Union Congress, Varna 1973 [Známka 2053] [Stamp 2053]
- Universal Postal Union, 1874-1974 [Známka 2104] [Stamp 2104]
- Universal Postal Union, 1874-1974 [Známka 2105] [Stamp 2105]
- Universal Postal Union, 1874-1974 [Známka 2106] [Stamp 2106]
- Universal Postal Union, 1874-1974 [Známka 2107] [Stamp 2107]
- Universal Postal Union, 1874-1974 [Známka 2108] [Stamp 2108]
- Universal Postal Union, 1874-1974 [Známka 2109] [Stamp 2109]
- All Trade Union Congress, Prague 1977 [Známka 2250] [Stamp 2250]
- 9th World Trade Union Congress, Prague 1978 [Známka 2304] [Stamp 2304]
- Socialist Youth Union 1970-1980 [Známka 2459] [Stamp 2459]
- 10th World Trade Union Congress, Havana 1982 [Známka 2524] [Stamp 2524]
- 60th Anniversary International Raiway Union [Známka 2530] [Stamp 2530]
- Universal Postal Union 1874-1984 [Známka 2652] [Stamp 2652]
- Universal Postal Union 1874-1984 [Aršik 2652] [Souvenir Sheet 2652]
- Universal Postal Union 1874-1984 [Známka 2653] [Stamp 2653]
- Universal Postal Union 1874-1984 [Aršik 2653] [Souvenir Sheet 2653]
- World Trade Union Federation 1945-1985 [Známka 2706] [Stamp 2706]
- 50th Anniversary of the Establishment of the Bowling Union in Czechoslovakia 1987 [Známka 2779] [Stamp 2779]
- Revolutionary Trade Union Movement [Známka 2790] [Stamp 2790]
- 11th Pan Union Congress [Známka 2790] [Stamp 2790]
- 125 Years of The Czechoslovak Mathematicians and Physicists Union [Známka 2801] [Stamp 2801]
- 125 Years of The Czechoslovak Mathematicians and Physicists Union [Známka 2802] [Stamp 2802]
- 125 Years of The Czechoslovak Mathematicians and Physicists Union [Známka 2803] [Stamp 2803]
- OSS: Thirty Years of the Socialist Communications Union [Známka 2810] [Stamp 2810]
- Soviet Union 1922-1987 [Známka 2816] [Stamp 2816]
- Universal Postal Union 1874-1994 [Známka 48] [Stamp 48]
- Association of the Czech Republic with the European Union [Známka 63] [Stamp 63]
- Universal Postal Union 1874-1999 [Známka 225] [Stamp 225]
- European Union Membership [Známka 394] [Stamp 394]
- Czech European Union Presidency [Známka 584] [Stamp 584]
- General Assembly of the Union of Czech Philatelists, Prague December 4, 2010 [Kupon 643] [Coupon 643]
- 150th Anniversary of the Foundation of the Union of Czech Mathematicians and Physicists [Známka 714] [Stamp 714]
- Unispace
- Unispace 82 Vienna [Známka 2544] [Stamp 2544]
- Unispace 82 [Aršik 2544] [Souvenir Sheet 2544]
- Unite
- Workers of the World, Unite! [Známka 592] [Stamp 592]
- Workers of all Countries Unite [Známka 651] [Stamp 651]
- Workers of all Countries Unite [Známka 652] [Stamp 652]
- Workers of the World, Unite! [Známka 723] [Stamp 723]
- United
- Be even more Harmonious, United, and Decisive, and your Will, the Will of the People, will be The Law of this Country. [Aršik 492] [Souvenir Sheet 492]
- United Healthcare Supports Building Socialism [Známka 670] [Stamp 670]
- United Healthcare Improves the Next Generation [Známka 671] [Stamp 671]
- United Healthcare Supports Building Socialism [Známka 672] [Stamp 672]
- Sports United for Socialism [Známka 674] [Stamp 674]
- United Nations [Známka 2126] [Stamp 2126]
- United Nations World Health Organization [Přepážkovy list 2215] [Minisheet 2215]
- 30 Years of the United Peasant's Cooperatives [Známka 2358] [Stamp 2358]
- 1945-1980 - 35th Anniversary of the Founding of the United Nations [Známka 2442] [Stamp 2442]
- United Nations [Známka 2541] [Stamp 2541]
- United Nations 1945-1985 [Známka 2689] [Stamp 2689]
- United Nations 1945-1985 [Aršik 2689] [Souvenir Sheet 2689]
- Helsinki Europe as a United House 1975-1990 [Známka 2945] [Stamp 2945]
- United Nations 1945-1995 [Známka 95] [Stamp 95]
- United Europe [Přepážkovy list 395] [Minisheet 395]
- The United Nations Educational, Scientific and Cultural Organization [Známka 909] [Stamp 909]
- Universal
- 16th Universal postal Union Congress, Tokyo 1969 [Známka 1791] [Stamp 1791]
- Universal Postal Union, 1874-1974 [Známka 2104] [Stamp 2104]
- Universal Postal Union, 1874-1974 [Známka 2105] [Stamp 2105]
- Universal Postal Union, 1874-1974 [Známka 2106] [Stamp 2106]
- Universal Postal Union, 1874-1974 [Známka 2107] [Stamp 2107]
- Universal Postal Union, 1874-1974 [Známka 2108] [Stamp 2108]
- Universal Postal Union, 1874-1974 [Známka 2109] [Stamp 2109]
- Universal Postal Union 1874-1984 [Známka 2652] [Stamp 2652]
- Universal Postal Union 1874-1984 [Aršik 2652] [Souvenir Sheet 2652]
- 19th Universal Postal Congress, Hamburg 1984 [Aršik 2653] [Souvenir Sheet 2653]
- Universal Postal Union 1874-1984 [Známka 2653] [Stamp 2653]
- Universal Postal Union 1874-1984 [Aršik 2653] [Souvenir Sheet 2653]
- Universal Postal Union 1874-1994 [Známka 48] [Stamp 48]
- Universal Postal Union 1874-1999 [Známka 225] [Stamp 225]
- Universiad
- Czechoslovak 1964 Universiad [Známka 1356] [Stamp 1356]
- Czechoslovak 1964 Universiad [Známka 1357] [Stamp 1357]
- Czechoslovak Universiad Brno 1965 [Známka 1413] [Stamp 1413]
- University
- Charles University 1348 [Známka 470] [Stamp 470]
- Charles University 1348 [Známka 471] [Stamp 471]
- Charles University 1348 [Známka 472] [Stamp 472]
- Charles University 1348 [Známka 473] [Stamp 473]
- Lomonsov University, Moscow [Známka 755] [Stamp 755]
- 35th Anniversary of Comenius University [Známka 816] [Stamp 816]
- Comenius University, Bratislava, founded 1919 [Známka 817] [Stamp 817]
- 35th Anniversary of Comenius University [Známka 817] [Stamp 817]
- Bratislava University 1465-1965 [Známka 1470] [Stamp 1470]
- Brno University 1919-1969 [Známka 1750] [Stamp 1750]
- Komensky University, Bratislava 1919-1969 [Známka 1751] [Stamp 1751]
- Olmouc University [Známka 2035] [Stamp 2035]
- O. Speniel: Charles University (1948) [Známka 2300] [Stamp 2300]
- Bratislava Technical University - 40 Years [Známka 2372] [Stamp 2372]
- Prague University of Applied Arts [Známka 2683] [Stamp 2683]
- Trnava University 1635 [Známka 2684] [Stamp 2684]
- Charles University, Prague [Známka 2849] [Stamp 2849]
- University Hospital, Motol - Prague [Známka 2855 1. vydání] [Stamp 2855 1st Issue]
- University Hospital, Motol - Prague [Známka 2855 2. vydání] [Stamp 2855 2nd Issue]
- Charles University [Známka 174] [Stamp 174]
- Charles University, Prague [Známka 453] [Stamp 453]
- Czech Technical University, Prague 1707-2007 [Známka 501] [Stamp 501]
- Unmanned
- Soviet Unmanned Interplanetary Station 10-4-1959 [Známka 1169] [Stamp 1169]
- Unmanned Multistage Rocket [Známka 1244] [Stamp 1244]
- Unmanned Station on the Moon [Známka 1245] [Stamp 1245]
- Unor
- Unor 1948-1949 [Kupon 501] [Coupon 501]
- Uprising
- Anniversary of the Slovak National Uprising [Aršik 408] [Souvenir Sheet 408]
- 10th Anniversy of the Slovak National Uprising August 29, 1944 - 1954 [Známka 796] [Stamp 796]
- 10th Anniversy of the Slovak National Uprising August 29, 1944 - 1954 [Známka 797] [Stamp 797]
- 15th Anniversary of the Slovak National Uprising 8-29-1944 1959 [Známka 1067] [Stamp 1067]
- 15th Anniversary of the Slovak National Uprising 8-29-1944 1959 [Známka 1068] [Stamp 1068]
- 120th Anniversary of the Slovak Uprising 1848 [Známka 1705] [Stamp 1705]
- Slovak National Uprising 1944-1969 [Známka 1778] [Stamp 1778]
- 25th Annibersary of the Prague Uprising [Známka 1829] [Stamp 1829]
- Slovak National Uprising 1944-1974 [Známka 2093] [Stamp 2093]
- May Uprising of the Czech people 1945-1975 [Známka 2136] [Stamp 2136]
- Slovak National Uprising 1944-1979 [Známka 2387] [Stamp 2387]
- 35th Anniversary of the Czech People's May Uprising [Známka 2438] [Stamp 2438]
- Slovak National Uprising 1944-1984 [Známka 2661] [Stamp 2661]
- May Uprising of the Czech People, 1945-1985 [Známka 2695] [Stamp 2695]
- Slovak National Uprising 1944-1989 [Známka 2902] [Stamp 2902]
- Uprka
- Joza Uprka 1861-1940 [Známka 1173] [Stamp 1173]
- Joza Uprka (1861-1940) [Známka 705] [Stamp 705]
- Joza Uprka Gallery [Známka 705] [Stamp 705]
- Ural
- Ural Owl [Kupon 817] [Coupon 817]
- Ural Owl [Aršik 853] [Souvenir Sheet 853]
- Uran
- Uran Worker's Resort (High Tatras) [Známka 2491] [Stamp 2491]
- Urn
- Urn Plant [Známka 2446] [Stamp 2446]
- Urx
- Eduard Urx 1903-1942 [Známka 1295] [Stamp 1295]
- Eduard Urx [Známka 2019] [Stamp 2019]
- Usak
- Kasim Usak Carpet [Známka 628] [Stamp 628]
- Use
- Cupon for Your Use [Kupon 354] [Coupon 354]
- Uses
- 2nd UN Conference on the Exploration and Peaceful Uses of Outer Space [Aršik 2544] [Souvenir Sheet 2544]
- Usti
- Usti nad Labem [Známka 1717] [Stamp 1717]
- Usti nad Labem [Známka 13] [Stamp 13]
- Usti nad Labem [Známkové sešitky 13] [Booklet 13]
- Usti nad Labem [Známka 656] [Stamp 656]
- Utagawa
- Utagawa Kunisada (1786-1865) [Známka 503] [Stamp 503]
- Utamaro
- Utamaro 1753-1806 [Známka 2998] [Stamp 2998]