The reasons for the positive association between families' background variables, such as parents' education, and children's academic achievement have not fully been clarified yet. The present study investigates children's intelligence and personality as potential mediators. A sample of 580 German high school students (mean age: M = 17.0; SD = 0.7) indicated the highest education of their parents and completed measures assessing their own personality and intelligence. Children's academic achievement was operationalized by grade point average. Children's intelligence, openness to experience and, marginally, conscientiousness partially mediated the association between parents' education and children's academic achievement. Even after controlling for children's intelligence, the mediating effects of those personality traits held. Results are discussed with regard to potential underlying processes. Copyright © 2010 John Wiley & Sons, Ltd.