The Avengers premieres in Hollywood

The movie, written and directed by Joss Whedon, stars Robert Downey Jr., Chris Evans, Mark Ruffalo, Scarlett Johansson, Jeremy Renner, Jackson and Chris Hemsworth - who were all in attendance at the premiere.

"This is very different for me because I am actually in the movie," said Jackson. "I am usually showing up at the end of them and kind of tying them together or being a tag line. So, it's kind of great to be a real part of it and to find out exactly what Nick Fury does, how he does it, a bit more about his personality, his strengths, his weaknesses and, I guess, his managerial skills, in terms of trying to get the Avengers initiative moving."

Robert Downey Jr. - who plays Iron Man - was accompanied to the premiere by his wife, producer Susan Downey, who recently gave birth to their son, Exton.

Johansson is the only female superhero in the film - something she sees as a bonus.

"Well I have to say I had it pretty good, I am here with Hollywood's hottest surrounding me all the time," she said with a smile.

Her co-star Chris Evans had nothing but praise for the starlet.

"She is an amazing girl. I have known her for 10 years and she is talented and smart and funny, really special human," he said.

For Mark Ruffalo, who plays The Hulk, working on the film was the most fun he's ever had:

"It's just a really great, fun, mercurial group of people, they are really witty, they got a great sense of humor. We were laughing all the time and that carried out. We hung out all the time offset as well as onset. It's a really good group," he said.

Australian actor Chris Hemsworth reprises his role as Thor in "The Avengers." He's set to play the character for quite some time.

"I signed to like six of them, so for the rest of my life I think. But we do the sequel to 'Thor' pretty soon. Look if people keep enjoying the films, then I am happy to keep pumping them out," he said.

"The Avengers" opens in theaters on May 4.