Police say the robber started his holdup in the greeting card aisle in the Rite Aid in the 8100 block of Roosevelt Boulevard just after 4:00 p.m.
He told the manager he had a gun, and ordered her around, even waiting 15 minutes for the safe to open, then taking cash from registers and various packs of cigarettes while he waited.
Police describe the ordeal as oddly calm.
Other customers at the Boulevard and Solly site were in the store but unaware during the robbery.
There were no injuries reported.
Police have not yet released the surveillance video but describe the suspect as a heavy set man in his 30s or 40s, with a dark complexion and a thin "chinstrap" goatee.
Anyone with information is asked to contact Philadelphia Police.