The road was closed and diversions were in place until about 8.30pm.
The Trustpower TECT Rescue Helicopter flew a 58-year-old Rotorua woman to Waikato Hospital with pelvic, chest and abdominal injuries and her husband was flown by the Taupo-based Greenlea Rescue Helicopter to Waikato Hospital.
The remaining victims were taken to Rotorua Hospital by St John Ambulance.
A witness to the crash told the Rotorua Daily Post she was following a car that was drifting across the road. She said she started honking the horn to warn the driver. The crash happened soon after.
Anyone with information is asked to call Rotorua police on (07) 349 9400.
Alternatively, you can contact Crimestoppers anonymously on (0800) 555 111.