Factual error: The vents that Hunt and his sidekick crawl down at CIA Headquarters are standard galvanized iron box vents; they are very common in the building trade. Try walking or crawling down one - you'll make a noise like the sky is falling down. People will be able to hear you for miles. Every person in that building would know somebody crawling about in the vent system. (This error applies to dozens of films, not only this one).
Trivia: An early draft of the script was set to feature several characters from the original series all being killed off to raise the stakes for the new characters. The producers wanted to bring back as many of the original actors as possible. All declined, as they felt it was disrespectful to the original series. As a result, only the character of Jim Phelps was brought back, albeit as a surprise villain and not a hero.
Trivia: Director Brian De Palma reportedly had creative difficulties with Tom Cruise, who was also a producer and thus had final say in the decisions made during production. While this has been disputed, many have noted the fact that De Palma did very little press for the film (including "politely excusing" himself from scheduled media interviews at the last moment) and never took up an offer to record an audio commentary for the film as evidence.
Question: Was Kreiger going to kill Ethan Hunt above the vault immediately after grabbing the disk from Ethan's mouth? Earlier when Ethan says, "Zero body count," Kreiger responds "We'll see," insinuating maybe he's still planning to kill somebody. As soon as Ethan's to the top, Kreiger grabs the disk, a quick, "Merci" (as if saying thanks, now goodbye), and the knife is already out, but luckily dropped. They are both so freaked out at such a near miss, Ethan doesn't even notice Kreiger was going to kill him. Did this cross anybody else's mind? Why else was the knife out to be dropped?