This study examined transactional development of mothers' beliefs (self-efficacy, success attributions of a child's success to maternal effort) and children's academic skills. Six hundred sixty-eight children and their mothers were evaluated twice: at the beginning of the first grade and at the end of the third grade. Mothers' beliefs were measured with a modified Teacher Efficacy Scale; math and reading skills were assessed with tests. The results showed that mothers' self-efficacy was not related to a child's academic skills. Mutual negative relations between attributions of a child's success to maternal effort and children's academic skills were identified. When children's initial skills were low, mothers' success attributions increased. In turn, mothers' higher success attributions at the beginning of school predicted children's lower skills at the end of the third grade. Mothers' higher education was related to their higher self-efficacy and lower success attributions. The findings emphasise the need to educate parents about attributions and the best ways to support their children's academic development.