Sahni was always interested in acting, and started his acting career with the plays of the
Indian People's Theatre Association (IPTA). He started his film career in
Bombay with the film
Insaaf (1946), followed by directed by
Khwaja Ahmad Abbas in 1946, Damayanti's first film,
Door Chalein in 1946, and other films. But it was in 1953, with
Bimal Roy's classic , that his true strength as an actor was first recognised. The film won the international prize at the
Cannes Film Festival. He followed it up with an encore in the 1961 classic
Kabuliwala penned by Tagore. Sahni's wife Damayanti, who was the heroine of his 1947 film
Gudia, died at a young age that same year. Two years later, he married his first cousin, Santosh Chandhok, later known as an author and television writer. He acted opposite heroines such as
Padmini,
Nutan,
Meena Kumari,
Vyjayanthimala and
Nargis in films such as
Bindya,
Seema (1955),
Sone Ki Chidiya (1958),
Sutta Bazaar (1959),
Bhabhi Ki Chudiyaan (1961),
Kathputli (1957),
Lajwanti (1958) and
Ghar Sansaar (1958). His
character roles in films such as
Neelkamal (1968),
Ghar Ghar Ki Kahani (1970),
Do Raaste (1969) and
Ek Phool Do Mali (1969) were well received. However, he is perhaps best remembered by the current generation for his picturisation of the legendary song "Ae Meri Zohra Jabeen" from the movie
Waqt (1965). Sahni appeared opposite
Achala Sachdev in the number. He also starred in the classic Punjabi film
Nanak Dukhiya Sub Sansar (1970) as well as the critically acclaimed
Satluj De Kande. His role as the angst-ridden, but stoic Muslim man who refuses to go to Pakistan during partition, in his last film
Garam Hawa, has often been called his best performance by critics. Balraj, however, could not see the completed film to rate his own performance, as he died the day after he finished dubbing work. The last line he recorded for the film, and hence his last recorded line is
Hindustani: "Insaan Kab Tak Akela Jee Sakta Hai?" which can be translated to English as: "How long can a man live alone?" == Later life ==