The 82-year-old German was only rescued after being spotted by coincidence by a local using a pair of binoculars while out for a walk with his family on Wednesday.
The elderly hiker had spent the whole night up a mountain near the village of Pertisau in Tyrol without any shelter, telling police he slept on a tree root.
He had set off on Tuesday in the direction of the Plumsjochhütte but after he failed to return by Wednesday morning his wife called emergency services.
Mountain rescue and the alpine police sent a helicopter over the region to try and find him but were unable to locate the lost man due to heavy fog.
Luckily for him the family were out walking that day and happened to spot him with the binoculars. The 82-year-old was then picked up by police and flown down the mountain.
He told the alpine police that he had got lost around twilight and was unable to find the way down by himself.