The man, whose identity was not immediately released, was standing on a traffic island on Rockaway Boulevard at Farmers Boulevard when the car hit him about 6:20 a.m., police said.
He was rushed to Jamaica Hospital and listed in serious but stable condition with severe injuries to his right leg, a police spokesman said.
The man may have stepped off the island and into the path of the oncoming car, police said.
The driver remained on the scene and was not expected to be charged with a crime, police said.
An FDNY spokesman initially said that a child was hospitalized along with the man, but police said no children were involved in the crash.