Objective: The authors investigated whether childhood specific learning difficulties (SLDs) predict later school performance in adolescents with ADHD symptoms (ADHDs) and how SLDs associate with educational aspirations. Method: In the Northern Finland Birth Cohort 1986 (n = 9,432), data about children were collected using questionnaires for parents and teachers at ages 7 and 8 and for parents and adolescents at ages 15/16. Information on school performance was obtained from a national register. Results: The occurrence of SLDs at 8 years was 19.9% (n = 1,198), ADHDs at 15/16 years was 8.0% (n = 530), and comorbid ADHDs and SLDs was 3.0% (n = 179). Having ADHDs but not SLDs or having both was associated with a significantly lower mean value in school grades for theoretical subjects. Adolescents with comorbid ADHDs and SLDs repeated a grade more often, and their educational aspirations were less ambitious than those in other groups. Conclusion: ADHDs and SLDs have a negative influence on academic achievements. (J. of Att. Dis. 2012; XX(X) 1-XX)