A wandering little street urchin, Ramu (Daisy Irani) earns his frugal living by selling sweets to school children, one of whom Soni (Baby Naaz) takes a great fancy for the urchin and there develops a bond between them. Soni is the only daughter ofa rich man, RaiSaheb (Rehman) and Geeta (Nishi). So when the festival of "rakhi" comes round, Soni pleads that she should be given a chance of tying the sacred cord to the hand of her pal. The wish is granted. The great day comes round. A host of rich children are invited for the party. Amidst great expectations, Ramu walks in the splendour-laden house, in his ragged clothes. carrying with him a dress as present for Soni. The appearance of Ramu on this scene, creates a furore, for the children immediately recognise him. RaiSaheb is enraged at the spectacle and refuses to permit his daughter to associate with Ramu. The party breaks up in a hurry. Soni is tearful. forRamu is forcibly sent out of the great house of wealth and luxury.
But as if in retribution for his snarling hatred towards a poor kid, the RaiSaheb is visited by a great misfortune. Soni is kidnapped by a gang of crooks who demand a lakh Rupees for the safe deliverance of the kid to her parents. Geeta and RaiSaheb are prostrate with grief. They seek police aid for the recovery of their child. But the disappearance of Soni also sets Ramu's little resources in motion. He promises Soni's father that he will seek out the hide-out of the crooks and deliver his dear Soni. But will he succeed? Will the rash gang of criminals be brought to book? Will Ramu get the happiness he seeks for? All these answers are contained in the balance of the story of the film which has among other things, the great Johnny Walker appearing for the first time as a jockey riding a Derby winner to victory, making love to Shammi !! It has the music of maestro Dutta, songs, dances, comedy, drama, thrills, spills, suspense-all that makes a real movie entertainment... that's our BHAI BAHEN.
[from the official press booklet]