Fire and Emergency NZ shift manager Scott Osmund confirmed one person had died, while people were trapped in at least two of the vehicles. Four fire appliances from Whangārei, Portland and Ruakaka were at the scene.
All but one of those trapped had been extricated from their vehicles by about 5.30pm.
Osmund said the crash site was about 200m south of Mangapai Rd.
"It's a fairly popular area for crashes like this," he said.
The crash prompted a tweet from Kaipara mayor Jason Smith, who called the road the "most dangerous highway".
"This wretched part of the State Highway network claims another life and wrecks more," he said.
"Leaders of the north want this to be 4 lane road to keep people safe."
An employee at the local petrol station said the crash had happened further up the road, by the bridge.
Traffic was moving but very slowly, he said.