Murli Prasad Sharma, better known as "Munna Bhai", is a Mumbai gangster who runs an extortion racket. His hideout doubles as a makeshift hospital, a clever ruse to fool his visiting parents, Shri Hari Prasad Sharma and Parvati Devi Sharma, who believe he is a real doctor.
During one annual visit, Hari reconnects with an old acquaintance, Dr. Jagdish Chandra Asthana, the dean of a local medical college who had helped found their village’s first medical centre. Hari suggests marrying his daughter to Munna’s childhood friend, Dr. Suman Asthana "Chinki" — a plan Munna both dreads and secretly relishes, preferring a real vocation.
Asthana discovers the truth when a maid reacts to Munna’s photo, exposing the lie to Hari and Parvati. Humiliated, the parents depart, and Munna vows to become a doctor to win back their respect. He secures a place in Asthana’s college with the help of Dr. Rustom Pavri, though the dean remains unconvinced that Munna deserves a medical degree.
Once enrolled, Munna uses a blunt, people-first approach—what he terms “common-sense treatment”—to challenge the cold, impersonal culture of the medical school and its professors. His empathy toward patients, especially those labeled incurable, endears him to hospital staff and patients alike, while causing friction with the administration. The atmosphere shifts as the hospital under Munna’s influence becomes a space where care and humor coexist.
In this new dynamic, Munna grows close to Dr. Suman Asthana "Chinki", though he hides his feelings behind lighthearted banter and misdirected schemes, even as Suman uses her own tricks to test him. He also heals people outside the formal curriculum: he helps a suicidal Karan find a reason to live, and he comforts the ailing father of [Dr. Pavri], among others. A bold move to cheer a terminally ill patient, Zaheer in a surprising ward-side gesture, leads to further conflict with Asthana, who seeks to discipline Munna.
After the dean’s failed attempt to remove Munna, he suffers an injury that keeps him in the hospital long enough for a turning point. When Anand Banerjee, a paraplegic patient who has been brain-dead for the last 12 years, appears to revive, the hospital sees a miracle. Suman makes a heartfelt case for Munna’s methods, and Asthana, moved by the evidence of healing and the patients’ faith, begins to question his own stance.
The outcome isn’t a traditional medical diploma for Munna, but a validation of his approach: his parents return, forgive him, and he marries Suman after she finally reveals her true identity. Together they open a real hospital in Munna’s ancestral village, proving that compassion can coexist with practicality. Circuit, Sankeshwar "Circuit" Sharma, marries a year later and has a son nicknamed “Short Circuit,” while Asthana resigns as dean and becomes the head doctor who embraces Munna’s methods. In the end, Anand Banerjee narrates the story to a group of children at the hospital, about to depart for Kolkata, closing a circle that begins with a ruse but ends in renewed faith in medicine’s human purpose.
