The robbery was reported at 8:59 p.m. at a store in the 3000 block of Geary Boulevard.
Two male suspects entered the business, one armed with a black semi-automatic handgun, and told an employee to give them the combination to the company's safe, according to police.
None of the employees in the store had the combination, so the suspects took cash from the registers and then ran away, police said.
No one was injured in the robbery.
No arrests had been made in the case as of this morning, according to police.
Anyone with information about the robbery is encouraged to call the Police Department's anonymous tip line at (415) 575-4444 or send a tip by text message to TIP411.