Sen is one of his nation's most politically active filmakers. After having studied physics at university in Calcutta, Sen worked as a freelance journalist, a salesman of patent medicines and a sound technician in a film studio. In the mid-1940s he joined the Indian People's Theatre Association and at that time began to read about and study film. The association had links to the Communist Party of India and this heralded the beginning of Sen's involvement with Marxist politics. In 1956 Sen made his debut with Raat Bhore (1956), the first of his 30 (as of 2002) films. Although his first film was openly political, he achieved national status as the director of a comedy, Bhuvan Shome (1969). Influenced by Italian neorealism and the work of fellow countryman Satyajit Ray, Sen used location shooting and non-professional casts in his early films. By the 1970s he was making wider use of symbolism and allegory. Although he remains politically committed, Sen feels that the "difference between party Marxists and a private Marxist like me is that others think they pocketed truth, whereas I am always in search of truth… " Sen's films have won numerous international awards. Kharij (1982), a scathing look at the hypocritical reaction of a bourgeois Calcutta family to the death of a servant boy, took home the Jury Prize from the 1983 Cannes Film Festival.

Was awarded the Padmabhushan by the Government of India in 1980.

Member of the jury at the Cannes Film Festival in 1982

Member of the jury at the Berlin International Film Festival in 1982

Member of the jury at the Venice Film Festival in 1983.

Member of the jury at the Venice Film Festival in 1996.