The man - only known as Sanjay from Mumbai, India - apparently caught his wife in bed with a neighbour.
She refused to apologise for her actions, so Sanjay climbed a nearby guava tree and has been there ever since.
Since being there he has been surviving on a diet of fruit from the tree as well as food handed up to him from relatives.
His sister spoke to The Asian Age newspaper, saying: "He eats and sleeps on the tree and even relieves himself from there."
Police say they are unable to intervene because he has not committed an offence.
Cholapur police confirmed: "The man is on a tree top for the last nine months over some domestic dispute."
Sanjay's wife has moved to live with her parents and is yet to apologise.
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