In July 2004, Parlour joined Premier League club Middlesbrough on a free transfer, signing a three-year contract at The Riverside. He played 60 games for Boro in two and a half years, and was an unused substitute in Middlesbrough's 4–0 defeat by Sevilla in the 2006 UEFA Cup Final. He was released from his contract on 25 January 2007, returning to his former club for a short period in order to train with them with a view to improving his fitness before finding employment in a new one.