- Mar 3 Luis Marden, American photojournalist (b. 1913)
- Mar 3 Peter Smithson, English architect, dies at 79
- Mar 4 Jaba Ioseliani, Georgian bank robber (b. 1926)
- Mar 6 John Sanford, American author (b. 1904)
- Mar 9 Bernard Dowiyogo, President of Nauru (b. 1946)
- Mar 11 Brian Cleeve, Irish author (b. 1921)
- Mar 11 Ivar Hansen, speaker of the Danish Folketing (b. 1938)
- Mar 12 Zoran Đinđić, 6th Prime Minister of Serbia (2001-03), assassinated at 50
- Mar 12 Howard Fast, American author (b. 1914)
- Mar 14 Jack Goldstein, Canadian-born artist (b. 1945)
- Mar 14 Jean-Luc Lagardère, French publisher (b. 1928)
- Mar 15 Paul Stojanovich, Reality TV pioneer (b. 1956)
- Mar 16 Rachel Corrie, American political activist, killed while trying to block an Israeli armored bulldozer at 23
- Mar 16 Ronald Ferguson, father of Sarah, Duchess of York, dies of cancer at 71
- Mar 17 Su Buqing, Chinese mathematician and educator (b. 1902)
- Mar 18 Adam Osborne, British computer pioneer (b. 1939)
- Mar 19 Michael Mathias Prechtl, German illustrator (b. 1926)
- Mar 21 Umar Wirahadikusumah, Fourth Vice President of Indonesia (b. 1924)
- Mar 22 Terry Lloyd, English reporter (b. 1952)
- Mar 23 Fritz Spiegl, Austrian-born journalist (b. 1926)
- Mar 24 Hans Hermann Groër, Austrian Catholic archbishop (b. 1919)
- Mar 26 Daniel Patrick Moynihan, U.S. Senator (b. 1927)
- Mar 27 Ricardo Munguia, Salvadoran aid worker
- Mar 27 Paul Zindel, American writer (b. 1936)
- Mar 29 Carlo Urbani, Italian physician (SARS) (b. 1956)
- Mar 30 Valentin Pavlov, Russian politician and Prime Minister of the Soviet Union (1991), dies at 65
- Mar 31 H.S.M. Coxeter, English-born geometer (b. 1907)