Kitty Carlisle, who normally was a panelist on To Tell the Truth (1956), filled in for Dorothy Kilgallen the week after Kilgallen died.
Louis Untermeyer resigned from the show after he was listed in 'Red Channels' during the McCarthy Era. He was a longtime friend of playwright Arthur Miller, who wrote that Untermeyer was so depressed about leaving the series he confined himself to his Brooklyn home for more than a year. The playwright also claimed that many years after the incident, a producer of the series, unnamed by Miller, apologized to Untermeyer and assured him that he had tried to keep him on the show, but numerous viewers demanded otherwise. Untermeyer was replaced by Bennett Cerf, who had appeared previously as a substitute panelist.
On several occasions Larry Blyden served as a guest panelist. Blyden would later become host of the syndicated version, replacing Wally Bruner.
All of the members of the "Rat Pack," with the exception of Frank Sinatra
, appeared as mystery guests on the show. Three of the five members, Sammy Davis Jr., Peter Lawford and Joey Bishop, not only appeared as mystery guests, but served on the panel as well. Sinatra didn't appear on the show until November 27, 1966 when he appeared as a mystery guest during the first game and then he moved to a seat on the panel. It was the only instance in which someone did that.
Dorothy Kilgallen, Steve Allen and Fred Allen are the only regular panelists who also were mystery guests on the CBS version of the show. Bennett Cerf was a mystery guest on the syndicated version.
One of the studios where the show was broadcast from eventually became the famous (or infamous) Studio 54.
The show's announcer Johnny Olson was a mystery guest on the April 4, 1965 broadcast and completely stumped the panel by using several different voices.
Martin Gabel holds the record for the most number of appearances as a guest panelist.
holds the record for the most appearances as mystery guest.
The mystery guest on the final CBS show was John Daly. Producers.
The 1966 - 1967 season was broadcast in color, but the color videotapes were discarded by CBS. Only black and white kinescope copies of the show were saved for posterity.
Moderator Daly used one signal for the panel: When he pulled his right ear lobe it warned them, usually Hal Block, that the questions were getting dangerously close to double entendre.
A 'What's My Line?' board game was introduced in the fall of 1955.
Ford, Carter and Reagan each appeared on the show before becoming president, but there was never a president who went on the show while in office. Lyndon Johnson used the show after the JFK assassination to advertise his liberal stand on the civil rights movement.
None of the panelists that were on the panel the night of the series finale (Arlene Francis, Bennett Cerf, Steve Allen and Martin Gabel) were on the panel the night the series debuted in 1950.