The incident occurred near Gopalpur village in the coastal district of Jagatsinghpur, 100 km from state capital Bhubaneswar Sunday evening. It came to light after police began a probe following a complaint by the man a day later.
The woman, a mother of two, said two men overpowered her when she was returning home from a temple. She managed to free herself and fled to the temple.
When one of the men followed her and tried to rape her, she chopped off his testicles with a sharp weapon.
The man has been admitted to hospital. No arrest has been made yet.