Rasathi Varum Naal is a 1991 Tamil horror film directed by Maniyan Sivabalan. The film features Nizhalgal Ravi, Kasthuri, Balambika in lead roles, with Nassar, Radha Ravi, Thyagu and Rajeshkumar playing supporting roles.

Radha (Kasthuri) lives a luxurious life with his widower father Rajasekhar (Nassar) in a palace, Radha will get married with the Inspector of Police Vijay (Nizhalgal Ravi) after finishing her studies. During a college tour in Pachaimalai Hills, Radha is saved from a near-drowning by her collegemates, she then finds a pendant in her pocket and she brings it at home.Radha starts to have creepy nightmares the night and her pet dog died in a mysterious way. One night, a spirit flees from the pendant and it enters into Radha's body. The possessed spirit of the girl-victim Rasathi (Balambika) wants to take revenge for a gang-rape what had happened 19 years ago ; the tormentors were Rajasekhar and his three friends Gowri Radha Ravi, Kabali (Thyagu) and Rajeshkumar (Rajeshkumar). The possessed Radha mercilessly kills Rajasekhar's friends one by one. Inspector Vijay, who is in charge of the case, finds out that Radha is the killer. What transpires next forms the rest of the story.