Emergency crews responded to a two-vehicle crash on Blanket Bay Rd, near the Dunedin-Port Chalmers Road, about 2.50pm today.
A Fire and Emergency spokesman said crews responded to calls of a ute towing a horse float and a car crashing.
Two crews from Willowbank and Port Chalmers worked to free a person trapped in one of the vehicles - a third appliance from Ravensbourne was needed to help extract the patient, the spokesman said.
Fire crews left the scene about 4.15pm.
An Otago Daily Times photographer at the scene said the crash had been head-on.
The car had been travelling north on Blanket Bay Rd and its hood was under the front of the ute, he said.
One of the car's occupants being treated by St John was in a school uniform.
A Hato Hone St John spokesperson said three patients, all in serious condition, were transported to Dunedin Hospital.
Two ambulances, one operations manager, and one first response unit attended.
A police spokesman said the road was now clear.
"The horse was not injured," he said.
