Based on control-value theory (CVT), we examined longitudinal relations between students' control and value appraisals, three activity-related achievement emotions (enjoyment, anger, and boredom), and math achievement (N = 1,716 fifth and seventh grade students). We assessed appraisals and emotions with self-report measures of perceived competence in math, perceived value of math, and math emotions, and achievement with school grades in math. All variables were measured in each of three consecutive annual assessments. Using structural equation modeling, we tested the CVT proposition that appraisals, emotions, and achievement show reciprocal relations over time. We hypothesized that (a) control-value appraisals influence the emotions, (b) the emotions influence achievement, and (c) achievement reciprocally influences appraisals and emotions. Supporting these hypotheses, the findings show that students' perceived competence and perceived value positively predicted their subsequent enjoyment and negatively predicted their anger and boredom, controlling for prior levels of these variables, gender, and prior achievement. Students' enjoyment positively predicted subsequent math achievement; anger and boredom negatively predicted achievement. Achievement showed reciprocal positive predictive effects on subsequent perceived competence, value, and enjoyment, and negative effects on subsequent anger and boredom; the effects on enjoyment and boredom were significant from Time 1 to 2 only. As posited in CVT, the effects of achievement on the emotions were mediated by perceived competence. In sum, the findings suggest that enjoyment, anger, and boredom influence students' achievement in mathematics, and that control-value appraisals and achievement are important antecedents of these emotions. Implications for future research and educational practice are discussed.