The aircraft, a Piper PA-28, set down at around 3:20 pm (local time)on the northbound side of the Major Deegan Expressway in the Bronx, in an area where the highway passes through Van Cortlandt Park.
The Federal Aviation Administration said three people were on board. All were taken to a hospital, but police and fire officials said neither the male pilot nor two female passengers appeared to have been badly hurt.
It wasn't immediately clear why the plane set down. It didn't strike any cars on the road, police said. The highway was closed and emergency personnel were on the scene.
FAA records indicated the plane was registered to an owner in South Salem, New York.
Patricia Sapol, 29, of West Point, was driving south on the highway with her husband when they saw emergency vehicles surrounding the downed plane, about 15 minutes after the landing.