American business publication Business Week has ranked Buffett at the first place in its annual list of "Top 50 American Givers", followed by software czar Bill Gates and his wife Melinda Gates.
On the third spot is George Kaiser and billionaire investor George Soros at the fourth, while former Chief Executive of Hilton Hotels William Barron Hilton stands at the fifth position.
"Many of America's ultra-rich continued to give big donations to charity in 2008, despite the worst financial crisis in decades. In the past year, seven philanthropists gave north of USD 200 million and nine gave more than hundred million dollars to causes ranging from wilderness preservation to fighting malaria.
"Warren Buffett and Bill Gates remain far and away the biggest givers overall...," the magazine said.
For the 2004-08 period, Buffett gave away USD 40,655 million while Bill & Melinda Gates donated USD 2,625 million.
Kaiser and Soros gave away USD 2,377 million and USD 2,214 million, respectively, during the same period.
Further, Hilton donated USD 1,700 million from 2004-08.
The list has been compiled using data from the magazine, The Chronicle of Philanthropy and Center on Philanthropy at Indiana University. Further, the figure of total amount of donation is based on public records and interviews with donors.