Fahmi Rahardiansyah, 19, has put his own kidney up for sale on an informal online forum in Indonesia called kaskus.co.id.
He said his father Muhamad Dik Mahmudi's blood pressure medicine is so expensive that selling his kidney is the only way he knows how to raise the money.
He is offering his kidney for Rp 50 million – the equivalent of around £3,500.
"I just want to help out with my father's medical expenses," said Fahmi.
He said he spent Rp 2.5 million (£170) on his father's treatment a few weeks ago at a community health centre in Balaraja, Tangerang, Indonesia, and another Rp 1.5 million (£100) on each intensive neurological therapy session.
The son, an assistant to a medical doctor at a small clinic in Bandung, West Java, earns Rp 1 million a month (around £70), while his father receives Rp 800,000 (£55) every month from his pension fund.
He said he knew that selling his organ may get him into legal trouble, but was ready to face the consequences.
"I know it's illegal and I'm afraid. But I don't mind being imprisoned as long as my father gets better," he said.