Darman's son, Jonathan, said his father, who lived in McLean, Va., was fighting acute myelogenous leukemia, The New York Times reported.
Besides serving the former President Bush as the director of the Office of Management and Budget, Darman worked in six Cabinet departments and the White House, serving five presidents.
During President Ronald Reagan's administration, Darman got a bipartisan Congress to pass Reagan's agenda.
He joined the Nixon administration in 1970 and worked with Elliot Richardson, helping to arrange the plea bargain that nudged Vice President Spiro Agnew out of office, then resigning with Richardson in the post-Watergate Saturday Night Massacre.
During the Reagan years, he was the principal legislative strategist.
After Bush lost to President Bill Clinton in 1992, Darman joined the Carlyle Group, was a professor at Harvard University's Kennedy School of Government and chairman of the AES Corp., an electrical utility.
Besides his son, Jonathan, Darman is survived by wife, Kathleen; his mother, two other sons, a granddaughter, a sister and a brother.