Thomas Bates, 30, was last seen in Lydney in Gloucestershire on March 2.
West Mercia Police said he was last seen in a blue/silver coloured Hyundai I40, with the registration number EX67CXZ.
The vehicle is believed to be in the Chepstow area.
Thomas is described as a white man who is 5ft 9ins tall, with a shaved head and close shaven with stubble.
He is of slim build but muscular at the top with tattoos of song lyrics and phrases on both arms.
He usually wears tracksuit bottoms and a big grey jacket with fur around the hood.
His family are extremely concerned for his welfare.
Anyone with information is asked to call 999.