Trevor Everton was last seen leaving a nursing home on Burngreave Road, Sheffield, at around 5am on Saturday May 20.
A South Yorkshire Police spokesman, said: " Police are growing increasingly concerned for Trevor’s welfare."
He is described as a 5ft 11in tall white man of large build with white receding hair and a white beard.
He has a number of tattoos on both his hands. He was last seen wearing a beige coat, dark blue bottoms and brown shoes.
Police said he generally stays local to the Burngreave area but has previously travelled to the Hull, Blackpool and Nottingham areas.
Anyone with information is urged to call South Yorkshire Police on 101, quoting incident number 439 of Saturday May 20 2017.