In 1998, she appeared in several notable films including Rounders, starring Matt Damon and Woody Allen's Celebrity opposite Leonardo DiCaprio. It was in 1998 that she also came to prominence and notoriety when she was featured on the cover of Vanity Fair magazine. Her appearance was both a triumph and a failure -- it brought her great attention, but her movies bombed. Dubbed the "It Girl of the Nineties" by the magazine, her career did not live up to the hype. Her early success was not sustained and she faced several lean years before a notable comeback with The Notorious Bettie Page in 2006. While major roles have been sporadic, Mol has been in more than thirty feature films. And though the films have often been small, she has worked for a number of important directors. Her first role came in Spike Lee's 1996 film, Girl 6. She said, "I was auditioning for Guiding Light and I was happy I got a Spike Lee movie, which was a tiny part, but all of a sudden I had Spike Lee on my resume. I didn't audition for day player anymore".

New York filmmaker Abel Ferrara took notice and cast her in two movies, The Funeral (1996) and New Rose Hotel (1998). She had a small role in Donnie Brasco (1998). By now, she was being typecast as "the girlfriend," which she attempted to change opposite Jude Law in Music From Another Room (1998), a romantic comedy. Unfortunately, no one noticed the film. For her second film with Woody Allen, 1999's Sweet and Lowdown, she played a minor role which the Greenwich Village Gazette called "notable". She played the victim of a con in the 2003 film, Heavy Put-Away based on the Terry Southern story. In 2006, she shared the lead in a romantic comedy, Puccini for Beginners, in which her character has a lesbian affair.

Mol worked with Mary Harron for two years as the director struggled to finance The Notorious Bettie Page: "I kind of felt like I lived with it for a while; certainly not as long as Mary Harron did but I got a good chance to really feel like I knew something about Bettie so by the time the role was mine and I was on set I was pretty confident. I felt like I really worked for it". The year 2007 was one of her busiest, with four films in production or in release, including a remake of 3:10 to Yuma starring Russell Crowe, and 'An American Affair' in which her character, Catherine Caswell, has an affair with John F. Kennedy. When released in February 2009, the film was harshly criticized by New York Times critic Stephen Holden, though he said that Mol's part was "quite well acted". In April 2008, she began filming Tenure in Philadelphia, working opposite Luke Wilson and Andrew Daly.

• "Life on Mars" .... Annie Norris (17 episodes, 2008-2009)
       - Life Is a Rock (2009) TV episode .... Annie Norris
       - Everyone Knows It's Windy (2009) TV episode .... Annie Norris
       - All the Young Dudes (2009) TV episode .... Annie Norris
       - Coffee, Tea, or Annie (2009) TV episode .... Annie Norris
       - Revenge of Broken Jaw (2009) TV episode .... Annie Norris
        (12 more)
• An American Affair (2009) .... Catherine Caswell
• Tenure (2009) .... Elaine Grasso
• The Memory Keeper's Daughter (2008) (TV) .... Nora Henry
• 3:10 to Yuma (2007) .... Alice Evans
• Trainwreck: My Life as an Idoit (2007) .... Lynn
• The Valley of Light (2007) (TV) .... Eleanor
• The Ten (2007) .... Gloria Jennings
• Puccini for Beginners (2006) .... Grace
• The Notorious Bettie Page (2005) .... Bettie Page
• Heavy Put-Away (2004) .... Mary
• The Shape of Things (2003) .... Jenny
  ... aka Fausses apparences (France: TV title)
• "Girls Club" .... Lynne Camden (9 episodes, 2002)
       - Hello, Goodbye (2002) TV episode .... Lynne Camden
       - Triple Header (2002) TV episode .... Lynne Camden
       - Thighs Wide Open (2002) TV episode .... Lynne Camden
       - The Young and the Meatless (2002) TV episode .... Lynne Camden
       - The Moment (2002) TV episode .... Lynne Camden
        (4 more)
• The Magnificent Ambersons (2002) (TV) .... Lucy Morgan
• Freshening Up (2002) (TV) .... Janelle
• Get Carter (2000) (uncredited) .... Audrey
• Attraction (2000) .... Liz
• Picnic (2000) (TV) .... Madge Owens
• Zoe Loses It (2000) .... Amber