This study examined the relationship of sport-specific knowledge to the development of children's skills in basketball. Two experiments were conducted. The first compared child expert and novice basketball players in two age leagues, 8-10 years and 11-12 years, on the individual components of basketball performance (control of the basketball, cognitive decisions, and motor execution) and on measures of basketball knowledge, dribbling skill, and shooting skill. Child expert players of both age groups possessed more shooting skill and more basketball knowledge. A canonical correlation analysis indicated that basketball knowledge was related to decision-making skill, whereas dribbling and shooting skill were related to the motor components of control and execution. Experiment 2 examined the changes in the individual components of performance, basketball knowledge, dribbling skill, and shooting skill from the beginning to the end of the season. Subjects improved in the cognitive decision-making and control components of performance across the course of the season, and basketball knowledge increased from the beginning to the end of the season. Only basketball knowledge was a significant predictor of the decision-making component at the end of the season. The overall results of Experiments 1 and 2 indicate that the development of the sport knowledge base plays a salient role in skilled sport performance of children.