Emergency services were called to the scene, in the Inverclyde town's Union Street, at about 20:30 on Sunday.
Firefighters used hydraulic cutting equipment to free some of the injured. Four men and one woman were then treated by paramedics at the scene.
It is understood two men sustained head injuries and another man was treated for a leg injury. One of the men was taken to Inverclyde Royal Hospital.
Five people have been injured after a car and taxi collided in Greenock.