The 20-year-old was struck in St Mary's Street, in Edinburgh's Old Town, at around 2.10am today.
Police Scotland said the car driver involved failed to stop after the incident and drove off.
Officers are now appealing for any witnesses to come forward.
The car is described as a silver mid-sized vehicle and the driver is said to be a white man in his 20s with short blonde hair.
The street was closed to traffic following the incident to allow investigations to be carried out.
It came less than two days after another man was injured in a ''frightening'' hit-and-run nearby.
The victim, also a 20-year-old man, was struck by a silver car on Edinburgh's South Bridge, near High Street, at around 4am on Friday morning. He received minor injuries in the incident.
Police said there is nothing to suggest the incidents are linked.
Anyone with information can contact police on 101, while Crimestoppers can be reached by dialling 0800 555 111.