The robbery happened Saturday morning at the PNC Bank branch on the 100 block of Old York Road in Jenkintown.
Police say the suspect claimed to have a gun but never actually showed one.
No one was injured but the man got away with an undisclosed amount of money.
The suspect is described as a brown skinned male, approximately 6' tall with a husky build.
He was last seen wearing a mustard colored, Carhartt type coat and a burgundy colored Phillies ball cap.
Anyone with information is asked to contact Abington detectives at 267-536-1100.
