This film originally had Dev Anand in the leading role, but following a spat between him and producer Nasir Hussain, he walked out of the film. When Shammi Kapoor was approached for the role, he told Nasir Hussain he would work in the film only if Dev Anand tells him personally he is not working in the film out of his own will, and that he is fine with him doing the film. That is what happened.
The song in the film "Tumne Mujhe Dekha" was the first song that Shammi Kapoor shot for after the early demise of his wife Geeta Bali who was a class in herself a great classic actress with mischievous dancing eyes and a great dancer.
At first 'Shammi Kapoor' was not happy with producer Nasir Hussain's choice of music director, Rahul Dev Burman. He wanted Shankarsingh Raghuwanshi, claiming that his music perfectly captured the rhythm of his body/dance. However, when Kapoor heard Burman's first song "Aaja Aaja Main hoon Pyar Tera", he changed his mind, impressed.
Director Vijay Anand later told his wife Sushma that he liked leading lady Asha Parekh's "naughtiness" so much that he repeated her in two more films. Kahin Aur Chal & Main Tere Liye. He also acted opposite her in the big hit film Main Tulsi Tere Aangan Ki (1978), directed by Raj Khosla. Asha, in turn, always complimented Vijay, saying that he was the "most fabulous director we ever had"
Shammi Kapoor's wife Geeta Bali died during the shoot of the movie and the love-drunk Kapoor went haywire and canceled the shoot. The movie was in-hold for 3 months by directer Nasir Hussain waited for Kapoor.