Gender differences in the development of children's and adolescents' academic self-perceptions have received increasing attention in recent years. This study extends previous research by examining the development of mathematics self-concept across grades 7-12 in three cultural settings: Australia (Sydney; N = 1,333), the United States (Michigan; N = 2,443), and Germany (four federal states; N = 4,688). Results of latent growth curve models document very similar patterns of self-concept development in males and females in the three settings. First, gender differences in favor of boys were observed at the beginning of the observation period (grade 7). Second, gender was not significantly related to self-concept change in either group, meaning that initial differences persisted across time. Third, the results provided no evidence that the form of the longitudinal change trajectories for mathematics self-concept differed across the cultural settings. This pattern of results is inconsistent with explanatory models that predict converging or diverging gender differences in mathematics self-concept. Furthermore, the results indicate that self-concept development may be highly similar across western cultural settings.