The shooting happened around 12:30 Sunday morning at a home on Mayor, near Mariposa.
Police say the victim was outside when a car pulled up to the house. Someone got out of the car and started yelling, and then opened fire.
Investigators say at least one bullet hit the woman in the leg.
She was taken to Community Regional Medical Center, and is expected to survive.
"We don't know if this incident is gang-related or the motive for this shooting. That is the focus of our investigation. We're waiting for addition information to come and hope for help from the community to provide assistance into why this happened," Lt. Tom Rowe of the Fresno Police Department said.
Authorities say at least two people were in the car, which at this time is described only as a white, two-door, possibly a mid-80's Pontiac Firebird.