The incident occurred at the Metro PCS store located at 3132 Kensington Avenue.
Police say a 27-year-old female employee had just opened the store for business around 9 a.m. when she was approached by one of the suspects.
The robber, who had a black mask covering his face, asked her to "keep quiet" as he pushed her against the wall and casually walked to the back of the store.
Surveillance video shows the thief grabbing several items from the back room as well as cash from the registers.
Click here to watch the surveillance video
A second masked man stood by the front door as a lookout.
Both suspects then fled the scene in an unknown direction.
There were no injuries reported during this robbery.
Police describe the first suspect as a male of unknown race and age, 5'10" tall with a thin build. He was wearing all black clothing with a black mask covering his face.
The second suspect is described as a male of unknown race and age, 5'7" tall with a thin build. He was wearing all black clothing with a black mask covering his face.
Anyone with information is asked to call Philadelphia police at 215.686.TIPS (8477) or text a tip to PPD TIP (773847).