Ronald Reagan is recovering from a successful one-hour operation on his broken right hip.
Mr Reagan's spokeswoman Joanne Drake said there were no problems with the former US President's surgery.
The 89-year-old was rushed by ambulance to the St. John's Health Centre after breaking his hip in an accident. He was in stable condition before surgery.
Mr Reagan suffered "a simple fall" at his home in Bel-Air, California, and was expected to need a pin installed in his hip. His wife, Nancy, was at his side.
His children were notified, including eldest daughter Maureen, who has been undergoing cancer treatments for melanoma at the same hospital since December 11.
Mr Reagan disclosed in November 1994 in a passionate letter to the American people that he had Alzheimer's disease and had begun the journey "into the sunset of my life".
The two-term president faded from the public eye a short time later and has rarely been seen outside his home.
He stopped going to his Century City office in 1999 but still made trips to parks and enjoyed strolls on the Venice Beach boardwalk with his Secret Service contingent.
At 69, Mr Reagan was the oldest man ever elected president when he was chosen on November 4, 1980, by an unexpectedly large margin over incumbent Democrat Jimmy Carter.