Officers responded to the collision in the 4600 block of Montgomery Drive at 1:08 p.m. and found the victim on the side of the road, police said.
Initial reports said that the driver had fled the scene before police arrived.
The male victim was checked by medical responders but was pronounced dead at the scene. His identity has not been released.
Witnesses told police that the victim had been struck by a light-colored newer model Mercedes and that the driver was a white or Hispanic man in his 30s with dark hair.
The suspect was last seen driving east on Montgomery Drive, possibly with front-end damage.
Montgomery Drive was closed for traffic while police investigated until about 5 p.m.
Anyone with information about the collision has been asked to call Santa Rosa police at (707) 543-4108.
