This study examined the main and interactive effects of athletes' goal orientations and perceived competence on sports motivation. One hundred and eleven handball players from eight high school teams of an average age of 5.59 years participated in the study. All the participants were asked to complete a series of questionnaires, which measured personal goal orientations, perceived competence, and sports motivation. A moderated hierarchical regression analyses revealed that task orientation positively predicted intrinsic motivation but negatively predicted amotivation. In contrast, ego orientation positively predicted identified, introjected and external regulation. Perceived competence positively predicted identified regulation. It was found that there were significant interactive effects for ego orientation with perceived competence and for ego orientation with task orientation in predicting external regulation and amotivation, respectively. The results suggest that athletes who focus on development of ability have high self-determined types of motivation, whereas those who focus on demonstration of ability have high controlling types of motivation. For athletes high in perceived competence, the high ego orientation increases, while the low ego orientation attenuates the external regulation. Regardless of high or low levels of ego orientation, the athletes' amotivational levels tend to be downplayed by their high task orientation, which exerts more impact on the low-ego-oriented athletes.