It was Bimal Roy who advised Yash Chopra against casting the Raj Kapoor, Shammi Kapoor and Shashi Kapoor as the three brothers. He reasoned that the kapoor brothers look like each other so much that anybody can point out that they are definitely related which will kill the whole separated brothers story arc.
Sunil Dutt was offered the film but refused it as he knew Raaj Kumar had best role. The makers insisted Sunil take the role. Sunil had never played the role of a playboy. As a favor to B.R. Chopra,Dutt took the film. As he predicted, Raaj Kumar was the one who walked away with all the credit for the film being a hit. However, Sunil Dutt's performance was also appreciated.
Dharmendra was offered the film but did not want to play the role of a elder brother. The role later went to Raaj Kumar.
The highest grossing Indian film of 1965.
Started a trend of films with similar plotlines of "loss and reunion".