A thorn in the heart) is a 1981 Indian Tamil-language film written and directed by Mathi Oli Shanmugam.

A remake of the Hindi film Kati Patang (1971), which in turn was based on the 1948 novel I Married a Dead Man by Cornell Woolrich, it stars Poornima Jayaraman and Pratap.

Nenjil Oru Mull is the first Tamil film for Poornima Bhagyaraj (née Jayaraman).

[1] The film is a remake of the Hindi film Kati Patang (1971), which in turn was based on the 1948 novel I Married a Dead Man by Cornell Woolrich.

[8] Nenjil Oru Mul was released on 11 December 1981,[9] and failed commercially.