Before he starred in Home Improvement, he appeared in local print and television advertising in Denver. He then appeared at a showcase in New York City, directed by Peter Sklar, where he was seen by a professional talent representative. This, and his interest in acting soon brought him to California, where he was cast in the role of Brad, the oldest Taylor child, in the show Home Improvement. His character was known for experimenting with different hair styles as well as being the child most often in trouble. He is one month younger than Jonathan Taylor Thomas, who played his younger brother Randy on the show.
In the middle of Home Improvement Bryan made an appearance as Steve on The Fresh Prince of Bel-Air in 1995. After Home Improvement ended, Bryan made brief appearances in many other television shows including (2002) Buffy the Vampire Slayer as Peter Nicols, (2005) Veronica Mars as Caz Truman, and (2006) Shark as Scott Natterson, as well as a guest appearance on an episode of Reading Rainbow. Additionally, he made a cameo appearance on MTV's I Bet You Will in which he portrayed himself and competed in a challenge where he wrestled female convicted felons. In 2001, he portrayed an ice hockey player in an episode of Touched by an Angel. He also appeared on Smallville in 2003 where he played Eric Marsh, a high school baseball player using steroids made from meteor rock. He was the second Home Improvement alum to make a guest appearance on the show after Jonathan Taylor Thomas. In 2005, Bryan appeared as Bryan Nolan in ESPN's TV movie Code Breakers. Bryan also guest starred in Cold Case (as the young murderer in the flashback scenes) and in 2008 as a young man hiring a hitman to kill his stepmother on the show Burn Notice.
Bryan's film roles include the school bully in the 1996 Sinbad comedy First Kid. He starred in the 1995 movie Magic Island as Jack Carlisle, and the 1998 TV movie The Principal Takes A Holiday. He also starred as Eric in 1999's The Rage: Carrie 2. Later, he played defender Harry Keough alongside Gerard Butler in the 2005 movie The Game of Their Lives otherwise known as The Miracle Match about the 1950 US upset at the World Cup. In 2006, he played as Clay in The Fast and the Furious: Tokyo Drift, then in the 2009 TV mini-series Meteor, which aired on NBC. He also played Thor in the made-for-TV Syfy channel film Thor: Hammer of the Gods. The film originally aired on November 29, 2009.