Madhuchandralekha movie revolves around Madhu aka Madhavan (Jayaram) who is a successful playback singer. Chandramathi (Urvashi) is his illiterate, rustic, betel-chewing wife with a bad habit of spitting in wrong places, and they have four children. It can be described as incompatible matrimony but still a happy one. Madhu loves his wife even though they are out of sync because she has brought him luck.
Here enters Lekha (Mamta Mohandas) who is a sophisticated urban model-cum-singer, who finds a place in the hearts of all the family members. Chandramathi thinks Lekha will be the perfect wife for her husband and a good mother for her children. How she goes about her plans of uniting Madhu and Lekha forms the rest of the story.