The robbery occurred Tuesday in the 700 block of Walker Avenue near the Grand Lake Theater, police said.
The suspect is described as a black man in his 30s, standing about 5 feet 7 inches tall and weighing 170 pounds. He has short hair and a silver "grill" in his mouth.
He is believed to have been in a truck before the robbery.
Police were able to obtain surveillance footage of the suspect and the vehicle.
Anyone with information about the case is asked to call Oakland police at (510) 777-3333 or (510) 238-3326.