As Leeds were relegated at the end of the 2003–04 season, Smith joined Manchester United for £7 million. The second chapter of his career began on 8 August 2004, in the Community Shield clash against Arsenal, scoring for the club with a swerving volley in the 55th minute, as United lost 3–1. He scored his first league goal against Norwich City, scoring the winning goal with a "stunning volley" in the 49th minute, having earlier setting up a goal for David Bellion.