He made his film debut in the 1966 film Aakhri Khat, directed by Chetan Anand, followed by Raaz, directed by Ravindra Dave, both of which were a part of his predetermined prize for winning the All-India United Producers' Talent Competition.[35] G.P. Sippy and Nasir Hussain were the first to sign Rajesh Khanna after he won the contest.[36] Aakhri Khat was India's entry for the Best Foreign Language Film at the 40th Oscar Academy Awards in 1967. Khanna in an interview to the newspaper The Hindu said:
Though 'Aakhri Khat' is my first film, I received my first break as a leading actor in Ravindra Dave's, 'Raaz', in 1967. My heroine was Babita, already a popular actress then. Though I had lots of confidence, I was shy in facing the camera initially. In my first three shots, I had to perform with stress on my body language and dialogue delivery. Though I was right with my dialogues, my movements were not up to the mark. Ravindra Dave explained me my scenes and movements very clearly correcting my way of walking.[37]