The Pulitzer board said the paper had "evoked a national outcry"
The Washington Post newspaper has won the United States' most prestigious journalism award - the Pulitzer Prize for Public Service Journalism.
The paper won the prize for exposing the poor hospital treatment of US soldiers returning home after being wounded in Iraq and Afghanistan.
The publication also won in five of 20 other categories.
Pulitzer prizes are awarded annually by Columbia University on the recommendation of an 18-member board.
The prizes recognise achievements in journalism, letters, drama and music.
The Washington Post won a breaking news award for its coverage of last year's Virginia Tech massacre, where 32 students and staff were killed in a gun rampage at a US university.
It was awarded four other prizes for national reporting, international reporting, feature writing and commentary.
The New York Times won awards in the investigative reporting and explanatory reporting categories.
Reuters news agency won the award for breaking news photography, for its picture of a Japanese videographer killed during last year's demonstrations in Burma.
Rodents and cockroaches
The Public Service award was won, the board said, for The Post's "exposing the mistreatment of wounded veterans at Walter Reed hospital, evoking a national outcry and producing reforms by federal officials".
The paper revealed that the Washington hospital was infested with rodents and cockroaches, and that the wounded servicemen had to wait months for disability pay.
The scandal led to the departure of President George W Bush's Secretary for the Army, Francis Harvey, and a senior general.
Each Pulitzer carries a $10,000 cash prize, except for the most prestigious - the Public Service award - which wins the recipient newspaper a gold medal.
Named after newspaper publisher Joseph Pulitzer, who died in 1911, the accolades were first awarded in 1917, and 2008's awards are the 92nd of their kind.