Police say the two elderly woman were hit just before 6:30 p.m. Friday on Jericho Turnpike.
The 75-year-old suffered serious head trauma and was rushed to Winthrop University Hospital where she died. The other woman suffered a broken femur and was hospitalized.
Police say the 18-year-old driver's SUV was impounded for brake and safety inspections. No criminality is suspected.
Police did not release the victim's names.