Most educational scholars agree that appropriate supervision of children is critical for positive youth development. Supervision is especially important during situations where children have a large degree of freedom and unstructured interaction, such as during recess. Despite the apparent importance of supervision of children at recess, there is little published research on the training of yard supervisors. The goal of the present study was to conduct a needs assessment and develop a customized training for yard supervisors at a public elementary school in an effort to help yard supervisors respond more effectively to student conflicts and promote a positive school climate. Needs assessment data used to inform the yard supervisor training were gathered through two methods: (a) playground observations of yard supervisor and student behavior and (b) yard supervisor interviews and student focus groups. Results of the needs assessment, and a description of the yard supervisor training developed from these findings, are presented, with particular emphasis placed on the implications of the study for practicing school psychologists.