Three elderly people died in the crash about 4pm on Thursday.

Police confirmed on Friday morning that the fatalities were that of a 76-year-old male from Young who was driving westbound in a 2004 Holden Utility and a 87-year-old male driving a 2013 Toyota Yaris with a 85-year-old female front passenger, with both from Lyndhurst.

The Mid Western Highway did not completely opening until nine hours later.

Chifley Police District Chief Inspector Glenn Cogdell explained that the incident was a head-on crash occurring in the eastbound lane just past Purcell Drive near Woodstock.

"About 4pm on Thursday afternoon, about 35 kilometres east of Cowra on the Mid Western Highway, there was a collision involving two vehicles," Inspector Cogdell said.

"As a result, unfortunately three people have passed away, with police attending, with ambulance, SES, Fire and Rescue NSW and RFS. The highway was closed until about 1.09am on Friday morning.

"Police are investing the cause of the crash and Police Science also attended. A report is being prepared for the coroner."

Inspector Cogdell said the scene indicates that the Holden Utility was on the incorrect side of the road at the time of the head-on collision.

NSW Ambulance duty officer Adam Parker said the scene was particularly distressing for those paramedics that were on scene.