Security camera video shows the 75-year-old man walk into the Capital One Bank on West 72nd Street on Dec. 20 at about 2:50 a.m.
The suspect followed from behind then punched the victim, knocked him to the ground and repeatedly kicked him.
The victim was taken to a local hospital for treatment to a cut to his eye.
No further details about the assault including whether there was contact between the assailant and victim prior to the incident were provided.
Cops asked anyone with information about the assault to contact them at the NYPD Crime Stoppers hotline t 1-800-577-TIPS (8477).
The public can also submit their tips by logging onto the CrimeStoppers website at https://crimestoppers.nypdonline.org/ or on Twitter @NYPDTips. All calls are strictly confidential.