A 34-year-old man died after his car hit a tree north-east of Tumut on Monday afternoon.
New South Wales Police are investigating the crash on the Three Ways Road, at Tumorrama about 2.30pm.
They said the man had been the only occupant of a blue Holden Rodeo travelling north when his car left the road.
Emergency services attended the scene and the driver was taken to Canberra Hospital where he died overnight.
A report into the death will be prepared for the New South Wales coroner.
Anyone with information about the crash is urged to call Crime Stoppers on 1800 333 000 or visit www.police.nsw.gov.au.