The aim of this two-year longitudinal study was to investigate the role and impact of prior mathematics performance, cognitive appraisals and mathematics-specific, affective anxiety in determining later mathematics achievement and future career orientation among Finnish adolescents. The basic ideas of the control-value theory, assumed to be culturally universal, and previous controversial results regarding the relationship between mathematics anxiety and mathematics achievement were tested in the Finnish cultural context with a longitudinal design. The key premise of the control-value theory is that control and value appraisals are significant determinants of both activity and outcome achievement emotions. Our results suggest that mathematics anxiety, a prospective outcome emotion, is determined by outcome expectancies (success or failure) and outcome value (the importance of performing well). They also suggest that anxiety as a negative affective emotion is a problem not only for those who perform poorly but probably also for certain pupils across all achievement levels. Compared with the performance level and with the boys, the girls exhibited inaccurately low outcome expectancies in mathematics. These low expectancies connected to the negative value of failure are a potential cause for their higher anxiety level. The educational implications of the findings are discussed. (Contains 6 figures and 2 tables.)