Munnabhai (Sanjay Dutt) is a dreaded gangster. While beating up a few foes he spots a beautiful girl in the crowd and his hot blood gets even hotter. He`s so smitten that he begins to behave like a loon and worries his fellow enforcers (Satish Kaushik and Annu Kapoor). A local doctor(Amitabh Bachchan) advises Munnabhai to woo and win the lady not realizing that the girl in question is his own little sister Komal (Aishwarya Rai).