On Friday a woman was killed following an accident at Blackheath, while on Sunday night another woman was killed following a three-car accident at Wentworth Falls.

The accident occurred at about 5pm on Sunday afternoon, with emergency services called to the Great Western Highway, near Sinclair Crescent after reports of a crash.

The female driver of a Kia Rio sedan died at the scene, while the female passenger was airlifted to Westmead Hospital in a serious condition.

The male driver of a Ford Everest SUV and the passengers - a woman and three children - sustained minor injuries.

They have all been to Katoomba Hospital with minor injuries where the driver will undergo mandatory testing.

The male driver and sole occupant of a Mercedes Benz sustained minor injuries and has been taken to Katoomba Hospital for treatment.

Officers from Blue Mountains Police District remain at the scene and have commenced an investigation into the circumstances surrounding the crash.

Investigators are appealing for any witnesses, or anyone who has dash cam vision, to come forward.

A report will be prepared for the Coroner.