- Awesome, Dear Boy: Jeremy Renner stated that working with Tom Cruise was a dream come true, since he's always idolized him as an actor. Renner did mention Cruise is a great actor, but even more a nicer guy.
- B-Team Sequel: J. J. Abrams was unable to return as director, as he was working on Star Trek (2009), though he did co-produce.
- California Doubling: Prague stood in for several scenes in Moscow. Prague Castle was used for some of the Kremlin scenes, most notably the second courtyard and the Spanish Hall. The Russian hospital was Prague's Hostel Chili. The local bar Ethan walks by after his escape was somewhere in New Town. Ethan gets picked up by the IMF secretary about a block away from the Hilton, but then doubles back and crashes the car into the Vltava all the way over at Mánes Bridge. Oddly enough, that's just upriver from Charles Bridge, which was used prominently in the first Mission Impossible movie. Prague and Budapest apparently share train stations as well. The satellite station at the end is also either in Bangalore or Hyderabad going by the sign on the service door (the official languages of both cities have near-identical alphabets) when the climax is set in Mumbai.
- Fake American: The English Tom Wilkinson as the IMF secretary.
- Name's the Same: William Brandt vs Willy Brandt, German chancellor (funnily and for a spy film fittingly enough, that wasn't his birth name but a pseudonym to hide from the Nazis). Even more fittingly, Willy Brandt resigned from his chancellorship after one of his closest employees turned out to actually be an East German spy.
- No Stunt Double: Tom Cruise performed the sequence where Ethan Hunt scales the outside of the Burj Khalifa tower himself without the use of a stunt double. The Burj Khalifa tower is the tallest building in the world at 2,722 feet, or 829.8 meters. Cruise dangled outside the tower at approximately 1,700 feet, or 518 meters.
- Uncredited Role: Tom Wilkinson, Ving Rhames and Michelle Monaghan all make uncredited cameos.
- What Could Have Been:
- An early draft lacked The Reveal that Julia didn't really die. Christopher McQuarrie, the eventual director of the next two Mission: Impossible movies, added this to the script to lighten its tone. That draft also had a different backstory for Brandt, who failed to protect two nameless IMF agents; McQuarrie replaced them with Julia to connect him to Ethan.
- Edgar Wright was considered to direct, but he was busy with Scott Pilgrim Vs The World.
- Tom Hardy, Anthony Mackie and Chris Pine were considered to play Brandt.
- Brandt was written and cast with the idea that he could take over as lead protagonist of the Mission Impossible movies in case Tom Cruise was ready to move on. Evidently Cruise stayed on, and Brandt had a more minor supporting role in Mission: Impossible Rogue Nation.
Trivia / Mission: Impossible – Ghost Protocol