Colin Barnfather, 54, was reported missing in Derby in the East Midlands.
Officers believe he travelled to Lochaber in the Highlands last month to go hillwalking and camping. It is thought he planned to walk in the Kinloch Hourn area of the west coast.
He is described as 5ft 8in tall and of medium build with short grey hair.
Police want to hear from anyone who may have seen Mr Barnfather or spotted a blue Honda car in the area.