Police received a report shortly after midnight that the man had gone missing in the Dau Forest area after hiking into the peninsula from a forest ranger station.
Heavy rain, darkness and difficult terrain caused him to lose his way and prevented him from finding his way back, police said.
Police, local militia, the Son Tra Peninsula and Danang Beaches Management Board, and firefighters joined the overnight search.
The man was found sheltering from the rain at about 3.20 am and was safely escorted out of the forest. He was in stable condition and later reunited with his family.