Greg Napora of Pacifica told police he returned home from work Thursday and found one of the dogs standing over his wife's body, the San Francisco Chronicle reported.
Rescue personnel attempted to revive Darla Napora, 32, but she was pronounced dead at the scene.
Greg Napora said he was able to get the dog into his back yard before police arrived but the dog escaped and was later shot and killed by police officers.
Neighbor Kathy Carlson said she saw Greg Napora outside his home.
"He was in the driveway all frantic, yelling. He had blood on his hands, blood on his shirt and blood down his pants," Carlson said.
"They are not barking dogs. They seemed friendly," she said, describing the pit bulls owned by the Naporas. "I have a pit also and he's an absolute angel. It's just really sad."
Animal control officials removed the Napora family's second pit bull from the home. Investigators said it probably wasn't involved in the attack.
In 2010, Jacob Bisbee, 2, was attacked and killed by three dogs in his stepgrandfather's Concord, Calif., garage. Five years earlier, Nicholas Faibish, 12, was mauled and killed by his family's pit bulls in San Francisco.