Tom Cruise’s Wildest ‘Mission: Impossible’ Stunt

Many movie stars like to boast about how they do their own stunts in their action movies, but Tom Cruise walks the walk. Specifically, he walks right out the window of the tallest building in the world.

Cruise has done some wild stunts in his movie career, but they all pale in comparison to the one he did for "Mission: Impossible - Ghost Protocol." The 49-year-old actor climbed up -- and also ran down -- the mirrored glass exterior of the Burj Khalifa, the 181-story, 2,723-foot-tall skyscraper in Dubai that holds the record for the highest structure ever built.

Take a look at the exclusive trailer for "Ghost Protocol," the fourth installment of the "Mission: Impossible" series. Then keep reading to find out how much of the stuntwork Cruise actually did himself.

So what percentage of the footage of Cruise hanging outside of the Burj Khalifa is actually him? According to producer Bryan Burk ("Star Trek," "Super 8"), every frame you see in the movie is really Tom Cruise. At a recent preview of scenes from the film, Burk said that Cruise did have a stunt double on set, but his job was only to test out the safety rigging. When the cameras were rolling, it was all Cruise. Which was good, because Burk said the stunt double was actually afraid of heights, and Cruise obviously had no problems with it.

See Stills from "Mission: Impossible -- Ghost Protocol >>

That's not to say there isn't a degree of movie magic at play here. Cruise was wearing a harness supported with cables that were later digitally erased. Still, there's no denying it took guts to get out there. Even his costars couldn't believe it. Simon Pegg, who reprises his role from "Mission: Impossible III," said in an interview, "I was there watching him doing it, which was terrifying... [He] has no fear. He just looked out and looked back in with a big smile on his face, like, 'Here we go!' And he was running round the side."

Cruise has made an effort in each "Mission: Impossible" movie to do a signature stunt that put him right in harm's way. In the first movie, he filmed a scene where thousand-gallon aquariums exploded around him, sending 16 tons of water in his direction. For "M:I2," Cruise scaled a sheer rock wall and dangled from a helicopter six stories about the ground. And in the third movie, Cruise was yanked into the air by one cable and crashed into the side of a car by another for the scene where an explosion tosses him around like a rag doll.

See Stills from "Mission: Impossible III" >>

While the shots of Cruise grasping onto the outside of the Burj Khalifa are pretty impressive on a computer screen, they are even more vertigo-inducing when seen on a giant IMAX screen. 25 minutes of the film were shot on IMAX's large-format cameras, and the picture will fill the seven-story screens. "Ghost Protocol" will open in IMAX theaters a few days before it is released everywhere on December 21."

To see more of Cruise just hanging out at the Burj Khalifa, check out this behind-the-scene footage.