It happened at 10:05 p.m. on Tuesday at the Community Green Market on White Plains Road in the Allerton section.
Surveillance video showed the men kicking and punching the 41-year-old victim.
Police say the store employee confronted two of the suspects who were eating grapes from the store's stand without paying for them.
The group of men then attacked him before fleeing with fruit.
The victim suffered bruising to his head and face and was taken to Bronx Municipal Hospital Center in stable condition.
Anyone with information in regard to the identities of the males is asked to call the NYPD's Crime Stoppers Hotline at 1-800-577-TIPS (8477) or for Spanish, 1-888-57-PISTA (74782).
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