Periya Thambi and Chinna Thambi are brothers and owners of a company. Gopalakrishnan is from a poor family, despite being a graduate, he cannot find a job. To support his family, he becomes the driver of Periya Thambi and Chinna Thambi. Periya Thambi's daughter Lakshmi and Chinna Thambi's daughter Priya fall in love with Gopalakrishnan. What transpires later forms the crux of the story.
During the shoot of Periya Idathu Mappillai, Guru Dhanapal was simultaneously making another film with Jayaram titled Raja Magal which did not release.[2]