Alistair Leech, 30, was last seen by his mother on Monday 15th March as he returned home on a train from Macclesfield station.
He then spoke to his mother on his landline phone when he returned to his house on Upper Chorlton Road in Whalley Range. Alistair has not used his bank account since Thursday 18th March and his mobile was left at home.
Concerns are growing because Alistair suffers from mental health problems and does not have any medication.
Police Constable Katie Parlatt said: "This man has been missing for over two weeks and we are growing increasingly concerned.
"Alistair has a tent and it's possible that he has gone camping, but because he doesn't have any medication, mobile phone or cash his family are obviously worried. If you see this man or have any information of his whereabouts, please let us know."
Anyone who thinks they may have seen Alistair is asked to contact Greater Manchester Police on 0161 872 5050 or the independent charity, Crimestoppers, anonymously, on 0800 555 111.
