The robbery happened shortly after midnight on October 3 inside the store located on the 2100 block of Lombard Street.
Police say the female suspect entered the store wearing a ski mask and threatened the employees with a knife.
She got away with an unknown amount of cash from the register before fleeing towards South Street.
The suspect is described as a black female, 40 years-old, 5'2 tall, 120 lbs. with a dark complexion and raspy voice. She was wearing blue jeans, gray hooded sweatshirt, dark blue mask and white gloves.
Anyone with information on this robbery should contact Philadelphia Police at 215.686.TIPS (8477) or text a tip to PPD TIP (773847).
VIDEO: Click here to watch the surveillance video