On the basis of an integrated theoretical approach to achievement motivation, the authors designed this study to investigate the potential influence of mastery goal, performance-approach and avoidance-approach goals, individual interest, and situational interest on students' learning in a physical education softball unit. The authors collected and analyzed data from 6th graders (N = 177), using correlation and multiple regression analyses. The results revealed that the mastery goal was a significant predictor for the recognition of situational interest, although individual interest directly contributed to acquisition of knowledge and skill. The findings suggest a need for researchers to adopt an integrated theoretical framework to explore the complicated connection between achievement motivation and learning in physical education. (Contains 3 tables.)