The Center for Disease Control and Prevention (CDC) reports that over 200,000 children every year are admitted to emergency rooms due to playground related injuries sustained at school. The National Association for Playground Safety recommends not only improving surface materials and equipment, but also improving adult supervision of children while at play. Yet, there are limited empirical studies in the literature that have examined the impact of a comprehensive training program to improve playground safety by improving supervisor knowledge and attitudes. The purpose of this study was to evaluate the efficacy of a comprehensive, stand-alone interactive multimedia computer-based training program for elementary school faculty to implement a school-wide behavior management program for playground environments. To do this, a randomized control trial comparing the experiences of playground supervisors, students, and staff from schools of a large urban school district was carried out. School was both the unit of randomization and the unit of analysis. The comparisons were measured by pre, post and follow-up assessments conducted by the investigators. Results suggest significant positive differences due to treatment in knowledge, beliefs and attitudes for playground supervisors, students, and staff.