Emergency services are responding to incident involving a person and a tractor on a private property in the Ikawai area, south of Waimate.
The accident was reported to emergency services at 7:50am a police spokeswoman said.
A St John spokeswoman said they were called to an incident on Waihuna Road South Canterbury.
Two first response units, an ambulance and a helicopter responded and were treating a patient in a serious condition.
WorkSafe has been notified the police spokeswoman said.