Cooperative behavior is important for well-functioning high school classrooms in which students trust their teachers and actively engage in academic tasks. Yet, discipline referrals for disruption and defiance are all too common and can result in lost instructional time and increased teacher stress. As such, more needs to be understood about trusting and cooperative interactions in classrooms. This study examined teachers' relational approach to discipline as a predictor of high school students' behavior and their trust in teacher authority. Findings from interviews and surveys with 32 teachers and 32 discipline-referred students supported a mediational model; the association between a relational approach to discipline and cooperative or defiant behavior was mediated by adolescents' perceptions of their teachers as trustworthy authority figures. Teachers may earn the trust and cooperation of students if they use relationship building to prevent discipline problems. Implications for school psychologists' consultation with teachers and the racial discipline gap are discussed. (Contains 2 tables and 3 figures.)