The driver of the cab, Jose Riviera, 30, of Copiague, was going northbound on Route 110 at about 12:33 a.m. when he struck the man, according to police.
The pedestrian was crossing the highway at the Hatcher Court intersection.
Riviera is not expected to be charged.
Police are looking for witnesses or help in identifying the victim, described as a white Hispanic in his 40s. His first name is Carlos, according to detectives.
Anyone with information can call Crime Stoppers anonymously at 1-800-220-TIPS.