Chambers' early career mirrored that of his twin brother James Chambers. Both played for school football teams - Grove Vale Primary School and Dartmouth High School, West Bromwich District and Sunday league team - Holy Name F.C. before joining West Bromwich Albion in 1996, and signing for West Bromwich Albion as apprentices in July 1997. After progressing through Albion's youth system, both twins turned professional in January 1999. In the 1998–99 season they became the first twins to represent England at any level when they appeared together during the World Youth Tournament in Nigeria. Adam made his first team debut for Albion on 9 September 2000, coming on as a substitute in a 0–0 draw away at Stockport County. His brother James, who had made his own debut during the previous season, played the entire match, making it the first time that twins had featured alongside each other for Albion. He scored his first and what turned out to be only goal for West Brom in a 2–0 win over Portsmouth on 24 February 2001. On 26 December 2002, they became the first twins to play together in the Premier League when they lined up against Arsenal, albeit that they were only on the field together for two minutes.