Our objective in this study was to test the new social-cognitive model of achievement motivation in a physical education setting. Research was conducted on a sample of 895 physical education students, ages 12 to 16 years. We measured perception of the motivational climate conveyed by the teacher, implicit beliefs of ability, perceived competence, 2 x 2 achievement goals and self-determined motivation. We carried out structural equation modeling to analyse the relationships among variables. Results showed that task climate positively predicted incremental belief, whereas ego climate positively predicted entity belief. Both climates positively predicted perceived competence. Incremental belief positively predicted mastery-approach goals, performance-approach goals and avoidance goals, whereas entity belief positively predicted performance-approach goals and avoidance goals. Perceived competence positively predicted mastery-approach and performance-approach goals. Mastery-approach goal positively predicted self-determined motivation, whereas performance-approach goal and avoidance goals negatively predicted self-determined motivation.