Furlong began his film career as John Connor in Terminator 2: Judgment Day, a role that earned him an MTV Movie Award for Best Breakthrough Role and a Saturn Award for best young actor. He was discovered for the part by casting director Mali Finn while visiting the Pasadena Boys and Girls Club. Furlong had no acting ambitions. He has stated, I fell into [acting], it wasnt something that I planned.
He followed this role with a string of moderately successful films and indies, sharing screen with Meryl Streep and Liam Neeson in Before and After, Tim Roth in Little Odessa, and Anthony Edwards in Pet Sematary Two.
In 1993, Furlong was featured in Aerosmith's music video for Livin on the Edge. This was also the only major Aerosmith video from Get a Grip not to feature Alicia Silverstone. In 1995, he starred in the film adaptation of Truman Capote's The Grass Harp.
In 1998, he starred in American History X alongside Edward Norton, and appeared in his first comedy role in Pecker, directed by John Waters. Of the role, he stated, It's true most of the characters that Ive played so far are kind of like suicidal. Really dark roles. Which I like. But I wanted to do something different and John gave me a chance to do that.
In 1999, he starred in the film Detroit Rock City.
In 2000, Furlong played a young inmate in Steve Buscemi's film Animal Factory. The following year, he took a role in I Cavalieri che fecero limpresa aka The Knights of the Quest, a film by Italian filmmaker Pupa Avati. Furlong worked steadily over the next few years, acting in five other films between 2003 and 2005.