The robbery happened around 9:12 a.m. on July 10th at the Wells Fargo Bank at 417 West Olney Avenue.
Investigators say the man presented the teller with a threatening demand note and was given an undisclosed amount of money.
After the robbery the man fled west on Olney Avenue.
The suspect is described as a black male, about 30 years old with a medium build. He had a beard and mustache and was wearing a yellow shirt with a black Nike logo and dark pants.
Anyone with information is asked to contact Philadelphia Police at 215-686-TIPS (8477) or through phillypolice.com.