A police spokesman said three cars were involved in the collision in Frankton Rd (State Highway 6A), near Potters Hill Drive, about 3.20pm today.
The road had been partially blocked and motorists were advised to avoid the area and expect delays, he said.
In a Facebook post, the New Zealand Transport Agency said the road had been cleared by 5pm.
Two Fire and Emergency NZ appliances and two ambulances attended.
A Hato Hone St John spokeswoman said four people were checked over by ambulance staff at the scene, but did not require further treatment.