A woman has died following a three-vehicle crash at Wentworth Falls on Sunday.
It follows a fatal car accident near Blackheath on Friday afternoon.
About 5pm on Sunday, emergency services were called to the Great Western Highway, near Sinclair Crescent, Wentworth Falls, after reports of a crash.
The female driver of a Kia Rio sedan died at the scene. 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 were all taken to Katoomba Hospital with minor injuries where the driver was to 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 have started 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.
Anyone with information about this incident is urged to contact Crime Stoppers: 1800 333 000 or https://nsw.crimestoppers.com.au.