To evaluate the role of temperamental task orientation in adolescents' academic success, we examined its relation to educational accomplishments in high school and college using longitudinal data. Participants (N = 110) were assessed at 15, 16, and 17 years of age with a follow-up at 24 years. Adolescent self-report and parent reports of task orientation at 16 were used to predict high school and college GPA, SAT scores, perseverance in college, and degree attainment. Task orientation related to high school GPA and accounted for variance above and beyond SES and IQ in predicting high school and college GPA. An interaction emerged between IQ and task orientation: increasing levels of task orientation were associated with higher GPA for students with higher intelligence, but not for those with relatively lower intelligence. These findings highlight the contribution of non-intellective factors to academic achievement in secondary and post-secondary education.