Taylor Lautner took home the awards for Favorite Movie Actor and Cutest Couple for New Moon's Jacob and Bella.
That was Katy Perry's reaction after getting a surprise sliming while presenting an award with actor Jonah Hill.
Teen superstars Justin Bieber, who performed his hit "Baby," and Selena Gomez, who was named Favorite TV Actress, were all smiles backstage.
Rihanna kicked off the awards show by singing a medley of her greatest hits.
Will Smith kicks it backstage with some new friends. His son, Jaden, 11, who costars in the upcoming Karate Kid, was a presenter.
Tina Fey and Steve Carell, who costar in the upcoming flick Date Night, got a healthy dose of green slime while presenting an award.
First lady Michelle Obama accepts the Big Help Award via satellite for her "Let's Move" campaign, which encourages kids to be active.
Miley Cyrus, who recently revealed plans to focus on her film career, picked up the award for Favorite Movie Actress for Hannah Montana: The Movie.
America's Top Model Tyra Banks kept a safe distance from the green slime.