ABSTRACT Purpose: The aims of the present study were to: (1) investigate the magnitude and direction of the cross-education effect in a unilateral sport skill (overhand throw) and (2) to establish which practice condition (dominant hand only or alternating hands) would yield the best results. Methods: The study involved three experimental groups of 11-year-old children (n = 59). The first group (n = 20) used only the dominant hand to throw the ball. The second group (n = 19) used the nondominant hand only, while the third (n = 20) alternated hands for each throw. A pre- and post-testing of both hands preceded and followed the intervention period. Results: The results of our study revealed no asymmetry in cross-education effect between the limbs for children’s overhand ball throwing. It was also shown that training both hands is superior to training the dominant hand alone. Conclusion: Our findings would be of particular interest to physical education teachers and coaches of unilateral sports who are advised to review their unilateral skill teaching methods as bilateral training offers a superior approach to augmenting the process of motor learning and performance.