In 1957, Mala Sinha was casted by Guru Dutt in the film Pyaasa. She played a memorable role of a woman who marries a rich man instead of a poor unsuccessful poet. The film Pyaasa is a classic in the history of Indian cinema. Mala Sinha's career took a huge leap as she signed three films with star actor Raj Kapoor: Parvarish (1958), Phir Subah Hogi (1958) and Main Nashe Mein Hoon (1959). Some of her unforgettable performances are Dhool Ka Phool (1959), Hariyali Aur Raasta (1962), Anpadh (1962), Gumrah (1963), Bahurani (1963), Jahan Ara (1964), Himalay Ki God Mein (1965), Aasra (1966) Aankhen (1967), Do Kaliyan (1968). She mostly preferred roles, which portrayed her as a strong women.
In 1966, while acting in the Nepali film "Maitighar", Mala Sinha fell in love with the hero of the film C.P. Lohani and married him. In the film Maryada, she did a double role and was starred opposite Rajesh and Raaj Kumar in the film. The film Phir Subah Hogi was based on Fyodor Dostoyevski's Crime And Punishment, Mala Sinha astonished everybody with her exquisite performance.