A young woman has been airlifted to hospital in a critical condition after a two-car crash on the Hume Highway near Gundagai on Sunday.

A NSW Police spokesperson said emergency services were called to the stretch of highway near the Dog on the Tucker Box monument about 2.40pm.

Police believed a Ford Falcon sedan was travelling north on the Hume Highway when it crashed into a Mitsubishi sedan turning onto the highway from a service station.

The driver of the Mitsubishi, a woman aged in her late teens or early 20s, was airlifted to hospital in a critical condition.

Paramedics treated the driver and passenger of the Ford, a man and a woman, before taking them to Wagga Wagga Base Hospital with serious injuries.

Cootamundra Local Area Command officers have established a crime scene at the site as investigations continue.

The Hume Highway is partially closed in both directions.