The incident happened around 11 p.m. on Drew Street at 101st Avenue in Ozone Park.
Authorities say the vendor's van was rear-ended, and the driver and other occupants of the car immediately jumped out to help.
The vendor sustained serious leg injuries. He was taken to Brookdale University Hospital, where he is listed in stable condition.
The driver who struck the van was being questioned by police, who may issue him motor vehicle violations.