Sundrapurushan movie tells Dr.Gevarghese (Mukesh) who runs a hospital for the mentally ill, in a hill station. One day a rich tycoon, Menon (N.F.Vargease) comes with his daughter Jyothika (Devayani) to the hospital. She is an extremely pampered girl, who is mentally unstable. To treat her, without her knowledge, Menon buys the hospital and makes her the MD. Suryanarayanan (Suresh Gopi) is a good singer who comes to the hospital in search of a job. Jyothika starts liking him and slowly falls in love with him.
When Menon notices the sudden change in his daughter, he is only happy to get them married. But soon he realizes that Suryanarayanan is married (Nandini) and has a daughter. He takes advantage of Nandini's greed for comforts and luxury, by buying them over. Thus Nandini forces Suryanaranan to fake a marriage with Jyothika.
Marriage changes Jyothika and she becomes normal and now Menon wants to get rid of Nandini. He plays dirty by making her sign on divorce papers and plans to send Suryanarayanan and Jyothika abroad.
Soon Nandini realizes the trouble and tries to meet her husband. Menon had by then poisoned Suryanarayan against his wife. Will the couple unite or will Suryanarayan opt for Jyothika forms the rest of this family melodrama.