Emergency services are at the scene of the two car crash on State Highway One north of the intersection with Otaihanga Road, near Southwards Car Museum.
Fire service spokesperson Murray Dunbar said the 111 call was received at 10.31am.
Crews from Paraparuamu and Waikanae are at the scene and are attempting to cut people from both vehicles at the scene, Mr Dunbar said.
The medical condition of the people in the cars is not yet known.
Both lanes of the highway are closed and extensive delays are expected.