The two-vehicle crash occurred at about 7.30pm on Thursday on the Hawke's Bay Expressway, State Highway 2, near its intersection with Watchman Rd in Napier.
Police initially said one person had been seriously hurt, but on Friday morning a police spokeswoman said two people were in hospital.
The northbound lane of the expressway was closed until roughly 11.30pm on Thursday while emergency services responded.
The Serious Crash Unit attended and conducted a scene examination.
A police spokeswoman said inquiries into the circumstances of the crash are ongoing. She clarified there had been no police pursuit prior to the crash.