Murli Prasad Sharma, nicknamed ``Munna Bhai`` is a crime don in the Mumbai underworld. Given that his father had wished him to be a medical doctor, he creates the faux Sri Hari Prasad Sharma Charitable Hospital (named after his father) and pretends to live in accordance with this wish whenever his father (Sunil Dutt) and mother (Rohini Hattangadi) visit him in Mumbai. But the truth reveals itself soon and leaves Munna`s parents heartbroken. Munna, in grief and despair, decides to gain revenge for his parents` humiliation by joining medical school to obtain a graduate medical degree. Then begins a comic riot and many lessons of compassion that Munna teaches those around him.