The actress explained to the Los Angeles Times that it was a major accomplishment for Maria Hill to stand out in a film that also featured Hollywood stars Robert Downey Jr, Samuel L Jackson and Mark Ruffalo.
"I feel like I was able to hold my own quite well… That was really important to me, because I was quite intimidated," Smulders commented. "Not only is it a different genre for me, but it's with some of the most talented actors in Hollywood!"
She went on to say that she grew to truly admire Maria as she researched the comic book character.
"I really got into her. She's like this ballsy chick who comes from this intense, tough background, military background," Smulders recalled. "It's cool playing a woman who has to be in this really tough world."
The How I Met Your Mother actress has previously appeared in a comic book spinoff as Shannon Bell in Smallville.
The Avengers is now playing in US and UK cinemas.
Watch a trailer for The Avengers below: