The crash happened in Dix Hills at the intersection of Deer Park Road and Old Country Road at about 9:45 p.m. on Wednesday, Oct. 5, the Suffolk County Police Department said.
SCPD said a 54-year-old West Hempstead man was driving a 2004 Pontiac sedan south on Deer Park Road and struck the man in the roadway.
The pedestrian was taken to South Shore University Hospital in Bay Shore for treatment of serious injuries, police said.
Police did not release his age.
The driver of the Pontiac was not injured, SCPD said.
Detectives asked anyone with information about the crash to call investigators at 631-854- 8252.
Click here to follow Daily Voice Massapequa and receive free news updates.