Deficits in appropriate play have been widely documented among children with developmental disabilities. However, there has been little research on the development of play or the relation between play and adaptive behavior in such children. The present study involved a longitudinal assessment of play and adaptive behavior among 13 preschool children with developmental disabilities. Children were assessed every 6 months over a 3-year period. Assessments included standardized ratings of adaptive behavior and videotape observations during unstructured free-play times in the preschool classroom. Adaptive behavior increased by almost one standard deviation from the first to the last round of data collection. Appropriate play was observed during approximately 20% of each 30-min observation and showed little overall change over 3 years of study. Observed play was primarily functional (57%) and exploratory (28%) with less constructive (5%) and pretend (10%) play. Adaptive behavior scores were not consistently correlated with the amount or type of play. The results suggest little overall relation between appropriate play and other major domains of adaptive behavior. Implications for play-based assessment and intervention in early childhood special education are discussed.