The film is about two pairs of identical twins separated at birth and how their lives go haywire when they meet in adulthood.
Raj Tilak (Utpal Dutt) and his wife (Shammi) are on a trip with their twin sons, both of whom they call Ashok. Since they look the same, they should be called the same, is Mr Tilak's reasoning. As fate would have it, they adopt another set of twins, both of whom they call Bahadur. An unfortunate accident then divides the family, leaving both parents with one child out of each pair of twins.
A few years later, Ashok (Sanjeev Kumar) is married to Sudha (Moushmi Chatterjee) and Bahadur (Deven Verma) is married to Prema (Aruna Irani). They all stay together with Sudha's younger sister Tanu (Deepti Naval). Into their lives enter the other Ashok, a detective novel aficionado, and Bahadur, a bhaang(an Indian concoction containing marijuana) lover. Now there are two Ashoks and two Bahadurs in the same city. This is more than their families, the Jeweller, the Taxi Driver and the Inspector can handle.