Community physical activity programs are a means by which children may be provided with appropriate physical activity, although it is not yet known how children register in these programs. In this research, registration of young children in community physical activity programs was assumed to be a product of decisions made by their parents. The purpose of the research was to explore the usefulness of the theory of planned behavior in predicting registration of children in a community physical activity program from decisions made by their parents. A simple random sample of 400 first-grade elementary school children resident in Heraklion, Crete, was selected. Their parents completed a questionnaire corresponding to the framework of the theory of planned behavior. It was concluded that the theory of planned behavior is valid in predicting the defined behavior.