Caesar began performing in New York after military service in the late 40s. He appeared in a revue called "Tars and Spars" at the Strand Theatre, followed by the comedy "Make Mine Manhattan" (both 1948). That same year, he guested on Milton Berle's TV show. By 1949, he was headlining "The Admiral Broadway Revue", a variety show broadcast simultaneously on both NBC and the Dumont Network and seen in every city in the US. It was on this show that he first worked with Imogene Coca, a long-time veteran of stage revues and herself a TV pioneer. The following year, producer Max Liebman, famous for his productions in New York and in the Catskill Mountains, teamed Caesar, Coca, Howard Morris and Carl Reiner for an NBC variety show called "Your Show of Shows". Although the program, which ran from 1950-54, never achieved the astounding ratings success of Berle's show or "I Love Lucy", it nevertheless became a classic which some historians believe had a far greater impact on the development of the medium. Each Saturday night for 90 minutes, America would see Caesar and the cast perform skits such as "History as She Ain't," satires on movies and other TV shows (e.g., "From Here to Obscurity"), a husband and wife skit, "The Hickenloopers", the fable of the great clock in the little town of Baverhoff, Bavaria, and many others. Caesar was at his best as an opera star babbling gibberish, as a turkey being eaten on Thanksgiving, or as Professor Ludwig von Votsisnehm. After 1954, the original quartet were broken up. Caesar tried three other shows with different casts, but never recaptured the magic.
By the 1960s, he was touring in his own comedy act and, relocated to Hollywood, occasionally acting in films and TV. He hosted "The Hollywood Palace", and had a supporting role in Stanley Kramer's romp, "It's a Mad, Mad, Mad, Mad World" (1963). In 1974, he had an even smaller role in "Airport 75" as a talkative passenger, and he would occasionally be seen as a guest on TV variety specials, often recreating the gibberish-speaking opera singer or Professor von Votsisnehm for an younger audience. In 1978, after years of addiction to pills and booze, Caesar was sober. He had a solid supporting part as Coach Calhoun in "Grease", a box office success. He repeated the role in "Grease 2" (1982) and began to find himself far more in demand, particularly for TV roles. He played Dr. Dustin Diablo in several "Munsters" revivals, Gryphon in "Alice and Wonderland" (CBS, 1985), and made numerous other guest appearances.
Caesar also appeared on stage with Coca and also in a solo show "Does Anybody Know What I'm Talking About?". "Your Show of Shows" and the subsequent Caesar TV shows are also famous for the writers who emerged from the stuffy room where they were forced to churn out 39 or more shows a year. Among them are Neil Simon, Woody Allen, Mel Brooks (who often has cast Caesar since although Caesar once almost threw him out an 18-story window), Mel Tolkin, Joseph Stein ("Fiddler on the Roof"), Michael Stewart ("Hello, Dolly!"), Lucille Kallin, and Selma Diamond. These writers have often used their experiences on "Your Show of Shows" for other work. Carl Reiner, co-star and writer on the series, created "The Dick Van Dyke Show" backstage with the writing staff of a variety show with a volatile, neurotic, egomaniacal host, Alan Brady. In the 1982 feature film, "My Favorite Year," Joe Bologna was "King Kaiser," a volatile, neurotic, egomaniacal and quick-fisted host of a New York produced variety show in the 50s. That film was written by Norman Steinberg, another alumnus of the writing staff. Simon wrote "Laughter on the 23rd Floor" about a group of writers working on a 50s TV show. It was no secret in Hollywood what the inspiration was for these projects.