In a longitudinal sample of Moscow children and adolescents (grades 2-11; n = 434, tested in 1990, 1992, and 1994), we examined the interrelations between their action-control beliefs about school performance and their actual school performance. A notable feature of this sample is that the students were exposed to an educational context that is relatively stable and consistent across the elementary and secondary school years. This feature provided us with a rare opportunity to study developmental changes that are relatively free of the pronounced context changes typically associated with the transition to adolescence (e.g. in the United States). The developmental trends of the action-control beliefs showed much continuity and cross-cultural generality, mostly extending age-related trends based on elementary-aged children. On the other hand, some of the trajectories showed evidence of distinct changes associated with the transition to adolescence. For example, although the participants' beliefs in their own ability showed a steady increase throughout childhood and adolescence, both: (a) their beliefs in their own effort and the accessibility of teachers and luck; and (b) their general control-expectancy decreased throughout childhood and adolescence. In addition, a consistent and reciprocal cross-time pattern of predictive effects between beliefs and performance emerged, with beliefs about personal ability being associated with changes in subsequent performance and vice versa. Given the few longitudinal studies and inconsistent findings in the field, the outcomes of this study shed new light on the dynamics of action-control development and strongly support the idea that beliefs about one's own action potential and actual performance form a synergistic and dynamic system of reciprocal effects.