A car has plunged seven metres into a creek on Brisbane's northside, with the driver trapped in the wreckage for some time before being taken to hospital.

Emergency services were called to Dorville Road in Carseldine about 12.10pm on Friday and found the car under the Cabbage Tree Creek bridge.

A police spokesman said a man, believed to be elderly, was behind the wheel when the car crashed and was the only occupant.

The Queensland Ambulance Service tweeted at 1.20pm that the patient was on his way to the Royal Brisbane and Women's Hospital in a serious but stable condition.

A QAS spokesman said the driver did not suffer major injuries as a result of the crash. Fairfax Media understands he may have suffered a medical incident behind the wheel.

The car was recovered from the dry creek bed about 12.45pm and the Forensic Crash Unit was investigating.