Detectives say a vehicle hit 24-year-old Walter Orlando Matute Penaranda while he was crossing Montauk Highway at Bay Avenue in Patchogue around 4:20 a.m. Sunday.
Penaranda was rushed to Brookhaven Memorial Hospital, where he is listed in critical condition after surgery.
Eyewitnesses say they saw a gray or silver two-door sedan with a rear spoiler drive away from the scene.
Based on witness accounts, there were additional vehicles traveling westbound at the time of the incident, and detectives believe there may be more witnesses to the crash.
Detectives are asking anyone who may have witnessed or has information on this crash to call the Vehicular Crime Unit at 631-852-6555 or anonymously Crime Stoppers at 1-800-220-TIPS. All calls will be kept confidential.