Only one hundred twenty missions include the famous warning that the tape will "self-destruct". Five say that the tape will "decompose", one says that it will "destroy itself", twelve instruct Briggs or Phelps to "dispose of" the recording, seven tell them to "destroy" it, and three contain no instructions, but Phelps destroys the recordings anyway. The remaining fifteen missions contain no recorded briefing at all.
Greg Morris and Peter Lupus were the only original cast members to remain on the show throughout the entire run, although Lupus was replaced by Sam Elliott for approximately half of the episodes in season five.
For several years, the series first season was not shown in syndication, due to the fact that many people had grown so accustomed to Jim Phelps (Peter Graves) being the leader of the team, that many viewers were shocked when they saw the first season reruns with Dan Briggs (Steven Hill) as the leader of the IMF.
The faceless figure shown striking a match in the opening credits was Series Creator Bruce Geller. It wasn't until the 1988 revival of the series that an established character (Jim Phelps) was shown lighting it.
Steven Hill left the cast after one season for two main reasons: because as an Orthodox Jew, and being unwilling to abide by the show's production schedule that would have required him to work on the Sabbath; and his disruptive behavior, often causing filming to shut down.
When the reel-to-reel tape recorder was playing the mission's instructions, it was actually in a "rewind" mode rather than a "play" mode. This was done because the tape moved too slowly to be believed when it was "playing".
Nearly every non-lead actor or actress that worked on Star Trek (1966) also appeared on this show. This is probably due to both shows having been filmed at Desilu Studios. Lead Star Trek (1966) performers, also guest appearing, include George Takei, William Shatner, and eventual series regular Leonard Nimoy.
According to Robert H. Justman in his book "Star Trek: The Real Story", this show's famous theme was not the first one written. Lalo Schifrin had written a main theme, but Creator and Executive Producer Bruce Geller decided that it was inappropriate. Instead, Geller used some chase music Schifrin had written for the end of the first episode. That throwaway musical cue became one of the most famous and recognizable television show themes in history.
This show (not including the 1988 sequel series) had the most episodes of any English-language spy series, with one hundred seventy-one episodes. Its nearest rival is The Avengers (1961), with one hundred sixty-one episodes.
In numerous episodes, a large, white, ornate archway with a metal gate was used, usually as the entrance to a prison. This was, in reality, the old main gate at Paramount Pictures Studios, where the series was filmed.
This series gave Peter Lupus (Willy) the chance to work under his own name. Most of his previous acting career was in Europe, where he played the lead role in sword and sandal mythological muscleman movies under the name "Rock Stevens". This also gave him a chance to act in a role that didn't rely mainly on his physique.
The main reason for Briggs, and later Phelps, looking through the photos to select the various members of the team for each mission was that many of the early episodes would feature guest stars as members of the team. However, once it became apparent that the same members were chosen every time, the practice was eventually abandoned.
During the first season, Martin Landau's face was not shown during the main title sequence. During that season, he was credited as making a "special appearance". It wasn't until season two that he was acknowledged as being a full cast member. This was because Landau, who at the time had a thriving motion picture career, didn't want to commit himself to the standard five-year contract that studios typically required of actors and actresses in a television series. Series Producer Bruce Geller wanted Landau badly enough, however, that he agreed to use him on a "guest star" basis during the first season. Landau signed one-year contracts at the beginning of the second and third seasons.
Television shows of the era that filmed at the same studios often shared minor cast members. It is common to see familiar faces on episodes of Star Trek (1966), Batman (1966), this show, and The Wild Wild West (1965).
Season one, episode twenty-three, "Action!"; season two, episode twenty-one, "The Town"; and season seven, episode eleven, "Kidnap" are the only ones in which the head of the IMF team did not receive instructions. In "Action!", Cinnamon Carter (Barbara Bain) received the instructions instead. It's also the only episode in the first season in which Dan Briggs (Steven Hill) did not appear. In "The Town", Phelps was on vacation when he uncovered a town of assassins who immobilize and try to kill him. In "Kidnap", Phelps was kidnapped and the information for his release was given to Barney (Greg Morris). In season five, episode four, "Homecoming", Jim arrived in his hometown to discover someone was killing the young women. There are only six episodes that are not "true missions". They include two of the above ("Homecoming" and "Kidnap") as well as season four, episode twenty-four, "Death Squad", where Barney was charged with murder; season two, episode nineteen, "The Condemned", where Phelps had to help a friend who had been charged with murder; and season one, episode eight, "The Ransom", where Briggs had to save a friend's kidnapped daughter. In season five, episode fifteen, "Cat's Paw", Barney's brother was murdered, and the team helped him bring those responsible to justice.
Of the one hundred forty-eight missions in which Phelps or Briggs received a tape recorded briefing, one hundred nineteen began with "Good morning", twenty-one with "Good afternoon", and eight with "Good evening".
Although the IMF usually received its instructions from a self-destructing reel-to-reel tape, the first two seasons often featured other methods. In early episodes, Briggs and Phelps got their instructions from other sources such as records and filmstrip projectors. The "tape scenes" for each episode (as they were known) were usually filmed in one block at the start of each season. Peter Graves said he never knew which episode would use which tape scene until it was broadcast.
Television Producer Bernard L. Kowalski, who'd been immensely impressed by the general mood and style of The Ipcress File (1965), requested that a similar ambiance and urgency be emulated for this show.
The show re-used many actors and actresses in different roles as different people. For example: John Vernon appeared as Colonel Josef Strom ("The Exchange"), General Ramon Sabattini ("The Falcon"), Ramone Fuego ("The Catafalque") and Norman Shields ("Movie"). William Windom appeared as Paul Mitchell ("The Fighter"), Stu Gorman ("Blues"), Alex Cresnic ("The Widow") and Deputy Premier Milos Pavel ("The Train"). This was a common practice on long running television shows in the 1960s.
The character played by Lynda Day George during seasons six and seven is now credited as "Lisa Casey." That name only came about as a result of Mission: Impossible (1988), however. When George was brought back in season one, episode seventeen, "Reprisal", to play the same character she had played during the original, the creators were concerned that there might be some confusion between her character and the one played earlier by Terry Markwell, who had also been named "Casey". Even though Markwell's character had been killed off in season one, episode twelve, "The Fortune", they abruptly re-christened the original Casey as "Lisa Casey", a name George's character had never used in any of her forty-one appearances during the original run of the series.
When Dan (Steven Hill) or Jim (Peter Graves) received instructions, the usual last words were "This tape will self-destruct in five seconds". However, the other instruction they would receive was "Please dispose of this tape by the usual means", whereby they would throw the tape into an incinerator, or toss it into a vat of acid.
In season five, the producers wanted to replace Peter Lupus with Sam Elliott, apparently because they thought Lupus was s bad actor. However, the show's fans were so upset with the decision, that Peter Lupus was kept on, with Sam Elliott appearing in approximately six episodes in season five, and one episode in season six.
Lalo Schifrin's score, played in a highly uncommon 5/4 time signature earlier popularized by Dave Brubeck's "Take Five" (1959), went on to achieve the dubious distinction of most parodied theme music closely paralleled by the The Twilight Zone (1959)'s eerie leitmotif trill.
When this show was bought by ARD for the West German market in 1967, only selected episodes from the first three seasons were dubbed (additionally, the episodes were cut down to standard running time of forty-five minutes). A few years later, they did the same with the later seasons (with new dubbing actors and actresses). When the show was broadcast on Kabel 1/Pro 7, all other episodes (except one) were dubbed as well (again with new dubbing actors and actresses). The last remaining episode was dubbed for the DVD release in 2006.
When Lynda Day George went on maternity leave during season seven, the explanation for her character's absence was that she was on special assignment in Europe. This is the only time that the reason for a regular cast member disappearance from the series is mentioned.
Academy Award winners Edmund O'Brien and George Sanders appeared on this show. O'Brien in season two, episode twenty, "The Counterfeiter", and Sanders in season five, episode twenty-three, "The Merchant".
In six season one episodes, Dan Briggs, (Steven Hill), is seen receiving his instructions and setting up the missions, but does not go on the mission. These are episode six, "Odds on Evil"; episode eleven, "Zubrovnik's Ghost"; episode thirteen, "Elena"; episode sixteen, "The Reluctant Dragon"; episode twenty-four, "The Train"; and episode twenty-eight, "The Psychic".
Despite the IMF being a secret organization, many of the team members had a very high public profile. They are featured on magazine covers: Cinnamon was "model of the year", Rollin was a well-know actor, Barney was founder/owner/president of an electronics firm, and Willy was a record setting weightlifter.