The possibility of gender-related differences in student motivation throughout their schooling was investigated in this study. Subjects were 538 elementary-school students, 1,519 high-school students, and 2,434 junior-college students from the Montreal (Quebec, Canada) area. The Adolescents Academic Motivation Scale was administered to assess students' motivational styles toward two main academic activities, "going to school" and "doing homework." Findings indicated that motivation does not occur under the same conditions for males and females. Results support the existence of gender-related differences across all levels of schooling. From grade 6 to junior college, girls are significantly more self-determined and less externally regulated and amotivated toward academic activities than boys who, in contrast, are significantly less self-determined. This gap in academic motivation is even more significant considering that more boys drop out of school than girls (in the Montreal areas, 42% compared to 28%, at the high school level). Because gender-related differences in motivational styles could have a great impact on teaching, learning and the evolution of our society, it seems imperative that future research focus on their antecedents. (Contains 32 references and 9 figures.) (TS)