3 Idiots story begins with two friends Farhan (madhavan) and Raju (sharman) who are well settled in life but they are on a mission- to locate their friend Rancho (Aamir). Well, Rancho was their room mate during the college days who dared to defy the system and believed in original thinking. Both Farhan and Raju come into the engineering college due to external factors and not their own interest but being with Rancho changes their outlook on life. There is also Pia (Kareena) who happens to be the love interest of Rancho but no one knows her whereabouts as well. Do Farhan and Raju get successful in their search? What are the experiences they have forms the rest of the story.