Dano acted in his first major film role when he was sixteen, playing Howie Blitzer, a teenage boy who becomes involved with a middle-aged ephebophile (Brian Cox) in "L.I.E." (2001). He then appeared in the television film "Too Young to Be a Dad" as a high school student whose life is disrupted when his girlfriend becomes pregnant. In 2004, he played a small role as young Martin Asher in "Taking Lives" with Angelina Jolie and Ethan Hawke. Additionally, Dano starred in the sleeper hit "The Girl Next Door", alongside Elisha Cuthbert, Emile Hirsch, and Chris Marquette. In 2005, he played supporting roles in "The King" and "The Ballad of Jack and Rose".