Upper elementary school students reported their self-perceptions of attainment, performance attributions, and achievement-related emotions in 2 consecutive school years in reading and math. In addition, teachers rated students’ academic performance, and in-class, observations were conducted to assess students’ task behavior during independent work times. Correlations revealed that students’ academic performance as well as a number of achievement-related cognitions and affects were stable over 1 year and across subjects. These findings suggest that, as students progress through school, they bring with them to a new class not only academic skills but also beliefs regarding their own competence. Altering students’ negative self-perceptions may, therefore, improve their school performance.