The man, who was hospitalized in grave condition, was pronounced dead at 5:42 p.m. Sunday, said Laguna Beach police Sgt. George Ramos.
The crash at El Toro and Laguna Canyon roads occurred about 12:30 a.m. Sunday, Laguna Beach police Capt. Jason Kravetz said.
The woman, identified by the coroner's office as Sandra Maldonado of Mission Viejo, was riding in a vehicle with her children, aged 5 and 8, and and going northbound on El Toro Road when it appears her vehicle and a Honda Pilot traveling in the opposite direction sideswiped one another, he said.
Maldonado was rushed to Mission Hospital Regional Medical Center in Orange, where she died from her injuries.
Her children were taken to Western Medical Center in Santa Ana, but they did not appear to be seriously hurt, Kravetz said.
"Alcohol doesn't appear to be a factor. We're still trying to determine which of the two vehicles veered out of their own traffic lanes,'' the police captain said this morning.
The woman's car spun around and the Honda rolled off the road into some bushes, where it came to rest on its wheels, Kravetz said.
The wife of the Honda driver, who was the other occupant in the SUV, was not injured, he said.