Amou Haji had refused to use soap and water for more than half a century, fearing it would make him sick.
The Iranian, who lived in the southern province of Fars, had avoided previous attempts by villagers to get him clean.
But, local media say, Amou Haji finally succumbed to pressure and washed a few months ago.
According to Iran’s IRNA news agency, he became ill shortly afterwards and died on Sunday.
In a previous interview, given to the Tehran Times in 2014, he revealed his favourite meal was porcupine, and that he lived between a hole in the ground and a brick shack built by concerned neighbours in the village of Dejgah.
He told the outlet at the time his unusual choices were down to “emotional setbacks” when he was younger.
Years of not bathing had left him with skin covered in “soot and pus”, IRNA said, while his diet had consisted of rotten meat and unsanitary water drunk from an old oil can.
He was also fond of smoking, being pictured on at least one occasion puffing on more than one cigarette at once.
Attempts to bathe him, or offer him clean water to drink, made him sad, the news agency said.
However, whether he holds the record for having gone the longest without taking a bath has been a matter of some debate. Back in 2009, there were reports of an Indian man who had – at that point – not washed or brushed his teeth for 35 years. What had happened to him since was not immediately clear.