It happened at the Rite Aid Pharmacy on the 300 block of East Allegheny Avenue around 12:15 p.m.
The suspect was caught on surveillance handing a demand note over to an employee and asking for money.
He got away with an unknown amount of cash from the register before fleeing east on Allegheny Avenue.
Police describe the robber as a Hispanic male, 20 years-old, 5'7" tall with a thin build and goatee. He was wearing a black bubble vest with a white hooded sweatshirt underneath, blue jeans, white gloves, and a dark colored knit hat with a snowflake design and tassels.
If you recognize this man, call police at 215.686.TIPS (8477) or text a tip to PPD TIP (773847).