Carmel Zerafa, 54, of Msida has been reported missing.
He was last seen on Tuesday wearing a top with white, blue and orange stripes, blue jeans and white sports shoes, the police said.
Mr Zerafa is five feet four inches tall, has tattoos on both arms and a shaved head.
Any information regarding Mr Zerafa can be passed on to the police on numbers 112 or 2122 4001.