Background: The purpose of this study was to characterize the temporal, social, and physical contexts for physical activities commonly reported in a diverse cohort of 753 boys and girls from fifth to seventh grade. Methods: Data were obtained from a multilevel longitudinal study, the Transitions and Activity Changes in Kids. The Physical Activity Choices instrument assessed previous 5-day participation in specific physical activities and their temporal, social, and physical contexts. Mixed model repeated measure analyses of variance and multinomial analyses examined sex differences and change over time. Results: Fifth grade boys and girls reported participation in similar activities at similar frequencies, which declined significantly by seventh grade. One temporal pattern, playing with younger children, changed over time from "both inside/outside" to "outside" school. Boys and females reported more activities performed in class/team groups over time. Most activities took place primarily at home for all participants in both grades. Conclusions: Boys and girls reported declines in the variety and frequency of activities from fifth to seventh grade. There were sex-specific patterns in physical activities and groups; however, all participants reported home as the primary location and a shift to class/team groups over time. Schools are well-positioned to provide additional physical activity opportunities.