Khan had wanted to cast Sabu Dastagir, a Hollywood star of Indian origin, as Birju. Dastagir travelled to India from Los Angeles, stayed in a hotel in Mumbai (then known as Bombay) and received a retainer. However, delays and obstacles in beginning shooting and getting a work permit for Dastagir led to his dismissal from the project. Dilip Kumar, an established actor in the Hindi film industry, had originally expressed an interest in playing Birju, which Khan found agreeable; Dilip Kumar agreed to play Shamu as well. However, Nargis objected that the public would not accept their casting as mother and son because she had done several romantic films alongside him. Sunil Dutt—with the experience of just one film—was finally cast, after Mukri, a comedian in the film, introduced him to Khan. Sajid Khan, the actor who portrayed the young Birju, was unknown at the time and was from a poor family from the Mumbai slums. Sajid's salary in the film was 750. He was later adopted by Mehboob Khan. Subsequently, Raaj Kumar was cast as Shamu and Rajendra Kumar as Ramu. "Mother India" was the first successful film and a turning point in the careers of Dutt, Raaj Kumar and Rajendra Kumar.