It happened at 11 p.m. on May 22.
Investigators say a 66-year-old woman was walking on the 4900 block of Spruce Street when one man ran up to her from behind and cut her off.
The suspect pointed a handgun at her and demanded her purse, while a second suspect rode his bicylce nearby as a lookout.
Click here to watch the surveillance video
Police say the woman put her hands in the air and the suspect grabbed her bag containing an iPad, bicycle tools, checks, ID and cell phone.
The pair then fled north on 49th Street.
The woman was not injured.
The first suspect is described as a black male, 18-26 years-old, 150 lbs. with a thin build and dark complexion. He was wearing a dark grey hooded sweatshirt, riding a BMX style bike and armed with a small handgun equipped with two barrels.
The second suspect is described as a black male in his late teens to early 20s with a thin build. He was wearing a zip-up hooded sweatshirt with what appears to be camouflage sleeves and riding a BMX style bike.
Anyone with information on this robbery should call police at 215.686.TIPS (8477) or text a tip to PPD TIP (773847).