Seven people have been injured in a head on collision near Okaramio, north-west of Blenheim.
Emergency services were called to State Highway 6 after two cars collided about 4.30pm this afternoon.
The Fire Service said it had to free two people from separate cars.
St John said five people were taken to hospital, three with serious injuries.
Two people had to be airlifted to hospital.
The road was closed earlier this afternoon, but one lane is now open.