Ian Jeffrey, also known as John Jeffrey, is 58 years old, was last seen on Monday 6th October in Motherwell.
He is also known to frequent Livingston, Wishaw and Lockerbie but may have travelled as far as Orkney or Northern Ireland.
He is described as white, Scottish, 6ft 4in tall, medium build, silver/grey hair, unshaven, with two sleeper earrings in left ear, a tattoo on his right forearm with four names, and with a West of Scotland accent. He was wearing a brown khaki hooded jacket, blue jeans and black trainers.
Police would like to appeal for anyone who has seen him to contact Police Scotland on 101 with information.