Background High levels of attentional and hyperactivity problems in school-aged children, even if subthreshold for attentiondeficit hyperactivity disorder (ADHD), are associated with academic under-achievement. Few large-scale, community-based studies have investigated the relationship between pre-school and adolescence. Aims To investigate whether pre-school hyperactivity/inattention and conduct problems are independently associated with academic outcomes at age 16. Method Data from the prospective, population-based Avon Longitudinal Study of Parents and Children (ALSPAC) were used. After adjusting for a broad range of confounder variables, the associations between parent-rated hyperactivity/inattention and conduct problems measured at age 3 and academic outcomes at age 16 (national General Certificate of Secondary Education (GCSE) examination results) were investigated (n = 11 640). Results Both early hyperactivity/inattention and conduct problems had negative effects on academic outcomes. In adjusted analyses, abnormal hyperactivity/inattention scores were associated with reductions of ten GCSE points in boys. Borderline and abnormal conduct problem scores were associated with reductions of 9-10 and 12-15 points respectively. Conclusions Pre-school hyperactivity/inattention and conduct problems carry risk of worse academic outcomes at 16.