This study investigated how two aspects of the classroom environment (teachers' emphasis on mastery goals and descriptive norms (i.e., the average student disruptive, prosocial, and achievement-related behavior in a classroom), moderated the relationship between student behaviors and coolness. The sample included 976 students nested in 54 fifth- and sixth-grade classrooms. Students completed peer nominations of coolness and three behaviors (prosocial, disruptive, and academic achievement). Students reported on the extent to which their teacher emphasized mastery goals in the classroom. The extent to which each of these three behaviors correlated with coolness varied across classrooms. The variability between classrooms in the behavioral correlates of coolness was not related to descriptive norms but was related to classroom mastery goals. In classrooms with a high-mastery goal emphasis, good grades and prosocial behavior were more likely to be perceived as cool. Our findings also suggest the need for future studies to examine the direct effect of prosocial descriptive norms on nominations of coolness. This study adds to a growing literature on how teaching practices matter for peer relationships in the classroom.