An Auckland man has been seriously injured after the car he was in crashed into a cow.

The 56-year-old was the passenger in a car that hit the cow at speed in Te Aroha.

The conditions of the driver and cow have not been established.

The injured man was treated for chest and abdominal injuries by St John paramedics before being flown to Waikato Hospital by the Waikato Westpac Rescue Helicopter.