The purpose of this correlational research was to examine the relationship between achievement emotions, motivation, and classroom engagement in mathematics among Turkish middle school students, and to determine how these three variables predicted academic achievement in mathematics. 549 seventh grade students in a province located in the south-west region of Turkey participated in the study. Relations among variables were examined by utilizing structural equation modeling. Results of this study provided evidence for the theoretical model that explained the relations between achievement emotions, motivation and classroom engagement and their contributions to a significant amount of mathematic achievement in Turkish contexts. In addition, it was found that the contributions of achievement emotions to engagement depend on whether they were activity- and outcome-focused or deactivating and activating emotions.