Authorities say someone got on the M14 bus on the Lower East Side, then punched the female driver several times in the head and ran off with her purse.
The incident happened near Houston and Columbia streets around 8:35 p.m.
The attacker disappeared into the Baruch Houses.
The driver, a 14-year MTA veteran, was treated at New York Downtown Hospital for cuts to her face.
Anyone with information is asked to call Crime Stoppers at 1-800-577-TIPS (8477).