Based in Mumbai, "Munna Bhai M.B.B.S." follows Murli Prasad Sharma (Sanjay Dutt), a goon nicknamed Munna Bhai, who stays with his friend and sidekick Sarkeshwar a.k.a. Circuit (Warsi), and pretends to be a doctor upon the arrival of his parents whose wish of seeing their son as a doctor is shattered after one of the father, Hari Prasad Sharma's (Sunil Dutt) old family friends, Jagdish Chandra Asthana (Irani), busts the truth regarding Munna's profession and practice, causing them to leave in shame and disgust. Vowing revenge against Asthana and his daughter "Chinki" who was his childhood friend, Munna unwittingly secures admission in a medical college whose dean, surprisingly, turns out to be Asthana himself. However, he ends up falling in love with a house doctor, Suman (Singh), unaware that she is "Chinki" herself, and brings about a climate of empathy amongst students and patients, which Asthana perceives as chaotic, thus creating a lot of hilarious situations and frictions between them.