The purpose of this study was to examine relationships between high school concert band directors' self-efficacy for classroom management, efficacious sources, and classroom management behaviors. Participants (N = 271) completed the Band Director Self-Efficacy for Classroom Management scale and responded to items about their demographic and school characteristics, formal preparatory experiences, stress from student behavior, support and trust, and satisfaction with recent classroom management. Additionally, participants rated their effectiveness for using classroom management behaviors. Participants' level of satisfaction with their recent classroom management was the strongest positive predictor of their self-efficacy for classroom management scores, followed by their ratings of parent resource support. When participants indicated higher stress from student behavior or higher administration resource support, they also had lower self-efficacy for classroom management scores. Results indicated that several classroom management behaviors predicted participants' self-efficacy, including establishing routines and procedures, keeping students on task, and rarely referring to the music score or lesson plan. Implementing and refining effective classroom management behaviors may improve the likelihood of directors gaining positive mastery experiences and lessen the influence of stress from student behavior on their self-efficacy for classroom management.