State Department spokesman P.J. Crowley said the surgery at George Washington University Hospital was completed Saturday morning on the 69-year-old Holbrooke and that his family was with him. He became ill on Friday while at work at the State Department.
Hospital officials did not respond late Saturday to an e-mail seeking more information.
Secretary of State Hillary Rodham Clinton visited the hospital on Friday night and again Saturday.
President Barack Obama early in his administration named Holbrooke special envoy for Afghanistan and Pakistan.
The veteran diplomat is perhaps best known for helping broker the 1995 agreement that ended the war in Bosnia.
He served as U.S. ambassador to the United Nations during the Clinton administration. He also was U.S. ambassador to Germany from 1993 to 1994 and then assistant secretary of state for European affairs.