 He started his first match for AIK against Halmstad in the fifth round, and soon became a regular in AIK's starting line-up.Moström scored his first goal in Allsvenskan when he scored the match-winning goal against Landskrona on 23 May 2004.After the 2006 season, AIK's new head coach Rikard Norling told Moström that he wasn't a part of his future plans and that he was free to find himself a new club.