Robert Hood, 77, from Kilwinning, North Ayrshire, was receiving treatment in Crosshouse Hospital, Kilmarnock, but was reported missing by staff on Sunday evening.
He was last seen in the hospital at 8.30pm that night and about half-an-hour later by a member of the public in Irvine Road, Kilmarnock.
Police said he required daily medication, and a helicopter, dog unit and specialist teams were involved in the search for him.
At around 5.30pm yesterday, his body was found on an embankment in Hillhouse Quarry Industrial Estate, Kilmarnock.
There are no suspicious circumstances and his family are aware, a police spokeswoman said.
A report will be sent to the procurator fiscal.