Two men walked into the Valero gas station at 1963 El Camino Real in Palo Alto at 6:30 p.m. Monday, one pulled out a handgun and the two men made off with about $400 from the station's cash register.
The two men were last seen running north on El Camino Real, Detective Brian Philip said.
In addition to the cash, one of the men also removed several cartons of cigarettes.
The two men were Hispanic, between the ages of 18 and 25. One had a thin build, wore a dark-colored cap, a black hooded sweatshirt, "Dickies" style pants and black shoes. The second man had a medium build, was wearing a dark cap, a white hooded sweatshirt, blue jeans and white shoes.
Anyone with information about the robbery is asked to call the Palo Alto Police Department tip line at 650-329-2190.