Is materialism systematically related to teenagers' learning motivation as well as actual learning outcomes? The reported research tested a theoretical model of associations among materialism, achievement goals, and exam performance among teenagers. Study 1 tested the theoretical model in 4 groups of teenagers drawn from 2 different educational stages (Year 9 and Year 12) and two societies of different cultural heritage (United Kingdom and Hong Kong). Results supported the model that materialism was associated with lower intrinsic mastery goals, and higher extrinsic performance goals in all of the 4 groups. More important, 1-year longitudinal data from Hong Kong (Study 2) showed that a materialistic value orientation at an earlier time point explained decreases in mastery goals and increases in performance goals a year later. Furthermore, earlier endorsement of materialistic values also predicted later deterioration of school performance. Theoretical and practical implications of the findings are discussed. (Contains 1 table, 7 figures, and 1 footnote.)