She reached to answer it and tumbled to the floor.
Gabor was rushed from her Bel Air home to the Ronald Reagan UCLA Medical Center in serious condition.
Her husband, Prince Frederic von Anhalt says Gabor broke her hip.
Hospital officials said early Sunday that family members were by her side but did not disclose any other details.
The actress is partially paralyzed from a 2002 car accident, which forced her to use a wheelchair. She also reportedly had a stroke in 2005.
Gabor is known for her many TV and film appearances dating back decades, including "Moulin Rouge" in 1952 and more recently in "The Naked Gun 2 1/2: The Smell of Fear" in 1991.
Gabor made headlines in 1989 when she slapped a Beverly Hills police officer when he stopped her for a traffic violation. She served three days in jail for that incident.