Berle began his career as a child model, posing for the advertising campaign for Buster Brown shoes. He entered films in 1914, appearing in the serial "The Perils of Pauline" and Mack Sennett's "Tillie's Punctured Romance". Reportedly, he appeared in over 50 silent films as a child performer. Berle began to perform on stage in 1920 in the Broadway production of "Floradora". Appearances in vaudeville, where the comedian perfected his wiseguy persona, led to engagements in editions of "Earl Carroll Vanities" and the "Ziegfeld Follies". He returned to features in "New Faces of 1937" (1937) and made sporadic appearances in the 1940s, including "Sun Valley Serenade" (1941) and "Always Leave Them Laughing" (1949).
After establishing himself in the developing medium of TV, Berle returned to features and the stage, searching for the role that would duplicate his success on the small screen. Like others comics who became TV personalities (e.g., Lucille Ball, Red Skelton, Carol Burnett, Sid Caesar), Berle had trouble shaking the public's perception of him as anything other than Uncle Miltie. His return to Broadway in Herb Gardner's play "The Goodbye People" (1968) was short-lived. He had moderate success touring in Neil Simon's "Last of the Red Hot Lovers" (1970) and later in the sex farce "Norman, Is That You?" (1975).
His feature work since 1960 has also been sporadic. He appeared as himself, hired to coach a showgirl (Marilyn Monroe) in comedy in George Cukor's "Let's Make Love" (1960), was a henpecked motorist in Stanley Kramer's all-star "It's a Mad, Mad, Mad, Mad World" (1963), partnered with Margaret Leighton as a mourner in Tony Richardson's sardonic "The Loved One" (1965), and delivered a dramatic portrayal of a Jewish gangster in "Lepke" (1975). He has continued to work into the 1990s, appearing in the 1995 direct-to-video children's film "Storybook".
On TV, Berle has made numerous guest appearances on comedies, variety shows and specials and dramas. An attempt to revive his variety show in the mid-60s failed to attract audience attention. Berle has proven himself capable as a dramatic performer on the small screen. He earned a Best Actor Emmy nomination for his dramatic performance in the "Doyle Against the House" episode of "The Dick Powell Show" (NBC, 1961) and a Best Guest Actor Emmy nomination for his turn as a veteran actor struggling with Alzheimer's Disease in an episode of "Beverly Hills, 90210" (Fox, 1995).