The incident happened on March 27 inside Fingers and Wings Pizza on the 3000 block of North 22nd Street.
The suspect can be seen on surveillance walking into the shop just after 9 p.m. and approaching the counter.
As he began to place an order, he pulled a handgun and demanded cash.
The robber got away with $400 from the register before fleeing on foot towards the 2100 block of West Toronto Street.
There were no injuries reported during this robbery.
The suspect is described as a black male, 30-35 years old and 5'8" tall with a thin build. He was wearing a blue hooded sweatshirt, dark pants, brown work boots and white gloves with orange palms.
Anyone with information is asked to contact police at 215.686.TIPS (8477) or text a tip to PPD TIP (773847).