A woman aged in her 60s died at the scene.

Emergency services were called to the Great Western Highway, near Evans Lookout Road, about 4pm on Friday following a head-on collision between a Kia 4WD and a Toyota Camry.

Police have been told the Camry struck another vehicle prior to colliding with the Kia.

The driver of the Camry, a woman aged in her 60s, died at the scene.

Two occupants in the Kia, a man and woman, have been taken to hospital. The man is believed to be in a critical condition.

The driver of the third vehicle wasn't injured but has been taken to hospital to undergo mandatory testing.

Officers from Blue Mountains Police District remained at the scene on Friday night and have commenced an investigation into the circumstances surrounding the crash.

Great Western Highway and Evans Lookout Road, Blackheath ...

Investigators are appealing for anyone who witnessed the crash, or has dashcam vision, to come forward.

A report will be prepared for the coroner.