When Venugopal, a medical representative gives a girl who runs into his cab a ride; he unknowingly gets involved in a murder.

Omanakkuttan is twenty-two years old and too lazy to hold down a job, which angers his father. His life takes a turn when he goes for his friend Sudi's sister's marriage and he marries her.

Midhunam movie is all about Sethumadhavan (Mohanlal) who has plans to start a biscuit factory near his house. But the bureaucracy and the corruption of the officials are the hurdles in front of him. Along with that he has to solve the problems in his family, which his brother (Innocent) and brother-in-law (Jagathy Sreekumar) creates. he marries his long-term fiancée Sulochana (Urvashi) who always cribs that he doesn't have love towards her, which he had shown before their marriage. How sethumadhavan succeeds in his life beating all the odds against him forms the rest of the story.