Lumet started his career in theatre before moving to film, where he gained a reputation for making realistic and gritty New York dramas which focused on the working class, tackled social injustices, and often questioned authority.

Other films include A View from the Bridge (1962), Long Day's Journey into Night (1962), The Pawnbroker (1964), Fail Safe (1964), The Hill (1965), Serpico (1973), Murder on the Orient Express (1974), Equus (1977), The Wiz (1978), The Morning After (1986), Running on Empty (1988) and Before the Devil Knows You're Dead (2007).

In 1935, aged 11, Lumet appeared in a Henry Lynn short film Papirossen (meaning "Cigarettes" in Yiddish), co-produced by radio star Herman Yablokoff.

[11] In 1939, at age 15, he made his only feature-length film appearance in ...One Third of a Nation....[12][13] World War II interrupted Lumet's early acting career and he spent four years in the U.S.

He organized an Off-Broadway group and became its director, and continued directing in summer stock theatre while teaching acting at the High School of Performing Arts.

As a result, while working for CBS, he directed hundreds of episodes of Danger (1950–1955), Mama (1949–1957) and You Are There (1953–1957), the latter a weekly series that featured Walter Cronkite in one of his early television appearances.

Lumet chose Cronkite for the role of anchorman "because the premise of the show was so silly, was so outrageous, that we needed somebody with the most American, homespun, warm ease about him", he said.

His first movie, 12 Angry Men (1957), a courtroom drama centered on a tense jury deliberation that was based on a CBS live play, was an auspicious beginning for Lumet.

According to The New York Times, the drama drew flack from the state of Massachusetts (where Sacco and Vanzetti were tried and executed) because it was thought to postulate that the condemned murderers were, in fact, wholly innocent.

He directed a live television version of Eugene O'Neill's The Iceman Cometh, which was followed by his film A View from the Bridge (1962), another psychological drama, from the play written by Arthur Miller.

This was followed by another Eugene O'Neill play-turned-to-cinema, Long Day's Journey into Night (1962), with Katharine Hepburn earning an Oscar nomination for her performance as a drug-addicted housewife; the four principal actors swept the acting awards at the 1962 Cannes Film Festival.

[20] Film critic Owen Gleiberman observed that Lumet was a "hardboiled straight-shooter" who, because he was trained during the Golden Age of Television in the 1950s, became noted for his energetic style of directing.

He captured that New York vibe like no one else because he saw it, lived it, breathed it – but then he had to go out and stage it, or re-create it, almost as if he were staging a documentary, letting his actors square off like random predators, insisting on the most natural light possible, making offices look as ugly and bureaucratic as they were because he knew, beneath that, that they weren't just offices but lairs, and that there was a deeper intensity, almost a kind of beauty, to catching the coarseness of reality as it truly looked.

He was able to draw powerful performances from actors, such as Ralph Richardson, Marlon Brando, Richard Burton, Katharine Hepburn, James Mason, Sophia Loren, Geraldine Fitzgerald, Blythe Danner, Rod Steiger, Vanessa Redgrave, Paul Newman, Sean Connery, Henry Fonda, Dustin Hoffman, Albert Finney, Simone Signoret and Anne Bancroft.

He did with Nick Nolte, Anthony Perkins, Armand Assante, Jane Fonda, Faye Dunaway, Timothy Hutton and Ali MacGraw, who referred to him as "every actor's dream".

[29] According to film historians Gerald Mast and Bruce Kawin, Lumet's "sensitivity to actors and to the rhythms of the city have made him America's longest-lived descendant of the 1950s Neorealist tradition and its urgent commitment to ethical responsibility".

[12] The Encyclopedia of World Biography states that his films often featured actors who studied "Method acting", noted for portraying an earthy, introspective style.

As a result, wrote historians Charles Harpole and Thomas Schatz, performers were eager to work with him, for they considered him to be an "outstanding director of actors".

Joanna Rapf, writing about the filming of The Verdict (1982), states that Lumet gave plenty of personal attention to his actors, whether listening to them or touching them.

[28] This theme is at the core of most of his movies, notes Rapf, such as his true-life films about corruption in the New York City Police Department or in family dramas such as Daniel (1983).

Lumet used the film to examine, with flashbacks, the psychological and spiritual scars with which Steiger's character lives, including his lost capacity to feel pleasure.

Lumet quickly became esteemed ... [and he] got a habit for big issues – Fail Safe, The Pawnbroker, The Hill, – and seemed torn between dullness and pathos.

... His sensitivity to actors and to the rhythms of the city have made him America's longest-lived descendant of the 1950s Neorealist tradition and its urgent commitment to ethical responsibility.

[41] Lumet was attracted to crime-related stories in New York City urban settings, where the criminals get caught in a vortex of events that they can neither understand nor control but are forced to resolve.

[17] Like other Jewish directors from New York, such as Woody Allen, Mel Brooks and Paul Mazursky, Lumet's characters often speak overtly about controversial issues of the times.

[44]Critic Justin Chang adds that Lumet's skill as a director and in developing strong stories continued up to his last film in 2007, writing of his "nimble touch with performers, his ability to draw out great warmth and zesty humor with one hand and coax them toward ever darker, more anguished extremes of emotion with the other, was on gratifying display in his ironically titled final film, Before the Devil Knows You're Dead".

She also wrote the screenplay for the film Rachel Getting Married (2008),[12][48] as well as co-creating two television series with Alex Kurtzman: The Silence of the Lambs sequel Clarice and Star Trek: Strange New Worlds.

[50] In 2015, Nancy Buirski directed By Sidney Lumet, a documentary about his career[51][52] that aired in January 2017 as part of PBS's American Masters series.

"[17] Jake Coyle, a writer for the Associated Press, agreed: "While Lumet has for years gone relatively underappreciated, actors have consistently turned in some of their most memorable performances under his stewardship.

[59] Al Pacino, on hearing of Lumet's death, stated that with his films, "He leaves a great legacy, but more than that, to the people close to him, he will remain the most civilized of humans and the kindest man I have ever known.