Surveillance images show the suspect inside the Wawa at 800 Cottman Avenue shortly after midnight Monday.
Police say the suspect asked for a pack of cigarettes and, when an employee opened the register, the suspect threatened the employee with a gun and demanded cash.
The suspect then ran off with an unknown amount of money.
He was last seen walking north on Rockwell Avenue.
The suspect was described as a white male, standing 5'5"-5'7" tall, medium build and brown hair. He was wearing a black puffy jacket, gloves, black pants, black shoes, and was armed with a handgun.
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.
