During his two decades in radio as a network Hollywood gossip reporter, Jimmy Fidler was one of the medium's most controversial figures. He came to Hollywood as an aspiring actor in 1919 and, after a career as a movie star press turned to radio, tattling on the stars, agent, chronicling their foibles, tantrums, and divorces. He is generally thought to have operated in the shadows of Hedda Hopper and Louella Parsons, but he was more feared by some studios and stars than either. His reviews of movies were caustic and blunt. He condemned those he considered "stinkers" with entertaining invective, and sometimes used the same adjectives for the people who had made them.

His trademarks included a film rating service (four bells for a top-notcher; one bell for a stink-eroo), a scathing series of "open letters" to the stars, his "notes from the little black book," and a celebrated and often-mimicked signoff "Good night to you, and I do mean you!" Many studios tried to blacklist Fidler from talking to their people. He was denied access to back lots, but this did nothing to stem the tide of his infuriating stories.

He quit CBS in 1941, charging that the network was pandering to the studios by insisting that he give good notices to "big" pictures. His long association with the Blue Network was soon tested, when actress Gene Tierney threatened to sue over a Fidler story that she had begun smoking cigars in an effort to acclimatize herself to her husband's smoke. An example of the kind of innocuous item that kept Fidler in constant Dutch was this "open letter' to Constance Bennett for the new year: "Resolved that the only splinters you get on the ladder of fame are those you get sliding down."

Fidler's appeal was based on a reputation for fearlessness (he always claimed to be just a guy trying to tell the truth) and a rapid-fire air delivery that reminded some of Walter Winchell. He packed his shows with material, often getting 3,000 words into the quarter-hour. His 1945 Hooper rating was 13.4, twice that of Hedda Hopper. By 1948 he was also writing a syndicated newspaper column, appearing in 175 papers and on more than 400 radio stations. He himself often varied the spelling of his name, signing publicity photos "Jimmie" in the 1930s and "Jimmy"' in later life. He continued syndicating his show into the 1970s.