Steven Rothschild, 72, was arrested and booked into the Sonoma County Jail. He is being held without bail, according to the sheriff's office.
Police said that around 11:40 p.m. Friday, Rothschild called 911 asking for a deputy to come to his home on the 700 block of Amherst Circle in Boyes Hot Springs, a census-designated place in Sonoma Valley.
Rothschild told police he had been in a fight with his wife and she was dead, according to the sheriff's office. When deputies and emergency workers arrived, they allegedly found Rothschild's wife, Juanita Rothschild, 67, unresponsive on the living room couch.
Juanita Rothschild appeared to have been seriously beaten, the sheriff's office said. The deputies didn't find any weapons.
Deputies and emergency medical personnel tried to revive her to no avail. She was pronounced dead at the scene.
The cause of her death is under investigation, according to the sheriff's office.