The purpose of this study was to describe associations between physical and social environmental features of preschools and physical activity behaviors of young children with developmental disabilities. Methods: A sample of 34 preschool-age children (mean age, 4.28 ± 1.07; male, 64.7%) with developmental disabilities participated in this study. Physical activity and preschool environmental factors were measured through direct observation using the Observational System for Recording Physical Activity in Children—Developmental Disabilities version. Children were observed approximately eight times over the course of a week, yielding a total of 11, 310 observation intervals. The number of intervals and percentage of time spent in physical activity across environmental contexts were calculated. Logistic regression analyses were conducted to determine associations between time spent in physical activity and features of the physical and social environment. (author abstract)