Lee Calam, 35, has not been heard from since Tuesday 8 March when it is believed he was seen at approximately 8pm in the Bishophill area of the city.
He is white, approximately 5ft 7in tall with a slim build and brown hair.
When Lee was last seen he was wearing a black fleece with a white logo on the left breast, blue jeans and dark coloured trainers.
Officers are concerned for Lee’s welfare as he has health issues and his disappearance is out of character.
Acting Inspector Richard Ogden, of the York Safer Neighbourhood Team, said: “I am urging Lee to make contact with the police as soon as possible so that we can confirm he is safe and well.
“I also need to speak to anyone who has seen Lee since Tuesday 8 March or knows where he is now.
“I am concerned about Lee as this behaviour is out of character. He has also missed a number of appointments in the last week.”
If you have any information that could help with this enquiry please contact Acting Inspector Richard Ogden at York Police Station on 0845 60 60 24 7 quoting reference number 12110038974. Or Crimestoppers anonymously on 0800 555 111.