It happened at the Homero Mini Market along Ella Street around 2:30 p.m. in the city's Kensington section.
Sources tell Action News that three suspects pistol-whipped and robbed the 65-year-old male store owner. They took $4,500 and then forced him to an area upstairs to take more items.
A 34-year-old man who was playing on a gambling machine inside the store was also shot in the leg during the robbery. Police say he was taken to an area hospital and placed in stable condition.
The suspects are still at large.
Anyone with information is asked to call police at 215-686-TIPS.
RELATED: Check the 6abc Neighborhood Safety Tracker