Balraj belonged to a Punjabi Khatri family. He had a brother Bhisham Sahni, who was a famous Hindi writer, playwright, and actor of that time.
When Balraj grew up, he went to Lahore, where he studied at Punjab University and completed his Masters degree in English Literature and held a Bachelor's degree in Hindi. Soon he got married to Dayamanti. Late 1930th - 40th were the years of his search of a permanent job. Only in 1946 Balraj started his film career.
In late 1930th Balraj with his wife moved to Bengal, were he started to work as an English and Hindi teacher at Rabindra Nath Tagore's Visva Bharati University.
In 1938, Sahni went to work with Mahatma Gandhi for a year and soon he went to England to join the British Broadcasting Network's Hindi service as a radio announcer. However, in 1943 he returned to India.
In 1946 that Sahni joined the Indian People's Theatre Association (IPTA), a group with which he started his acting career.
His film career Balraj started with a film "Insaf" in 1946. "Dharti ke Lal" and "Door Chalein" were his next of releases in the same year.
Sahni's wife Damayanti died at a young age in 1947, who was the heroine of his film, Gudiya (1947) and two years later he married his first cousin, Santosh Chandhok, later known as an author and television writer.
He continued acting in different films and became very liked and popular.
He alsoacted in the classic film "Nanak Dukhiya Sub Sansar" (1970).
Besides being a brilliant film actor, Balraj was a gifted writer. His book "Mera Rusi Safarnama" earned him the 'Soviet Land Nehru Award'.
