Two elderly bushwalkers missing in Blue Mountains

Police say the alarm was raised on Sunday when the 69-year-old man failed to keep an appointment and a search got underway.

The 81-year-old man's car was found in the car park of Dunphy's campground.

Both men are described as experienced bushwalkers and police believe the trail they intended to take was within their capabilities.

A command post has been established at Dunphy's campground with local police, the rescue squad and SES involved in the search.