Performance at school is affected not only by students' achievement goals but also by emotional exchanges among classmates and their teacher. In this study, we investigated relationships between students' achievement goals and emotion perception ability and class affect and performance. Participants were 949 Greek adolescent students in 49 classes and their Greek language and mathematics teachers. Results from multilevel analyses indicated that students' mastery-approach and performance-approach goals were positively related to positive affect whereas performance-avoidance goals were negatively related to positive affect. At class-level, relationships between achievement goals and affect were moderated by students' emotion perception ability. These findings highlight the importance of emotion abilities and their role in motivational processes for class-level outcomes.