Childhood play is a major arena for development of knowledge, skills, and attitudes that permit productive adult behavior. Occupational therapists must assess and treat play dysfunctions in order to promote normal development. The purpose of this study was to examine the reliability and validity of a play assessment tool, the Preschool Play Scale. Ninety children were observed and rated on the Preschool Play Scale, Lunzer’s Scale of Organization of Play Behavior, and Parten’s Social Play Hierarchy. Data were analyzed using bivariate correlation coefficients. Significant results suggest that the Preschool Play Scale will yield objective, stable, and valid measurements of play for normal preschool children when administered by trained observers. Recommendations for further study of the Preschool Play Scale are given.