The robbery happened in the 6100 block of Harbison Avenue on June 13th.
Police say the suspect pulled out a knife and ordered an employee to empty the cash register.
He got away with $300.
The suspect is described as a black male, between 20 and 30 years old, standing 5'7" to 5'9" tall. He was wearing a blue hooded sweatshirt and black shorts.
Anyone with information is asked to contact Philadelphia Police at 215-686-TIPS (8477), text a tip to PPD TIP (773847) or through PhillyPolice.com.