Background: The evidence for a role of androgens in human aggression is less convincing than in animals. We examined the relationship between androgens and aggression in prepubertal boys who were diagnosed as suffering from severe aggression and antisocial behavior. Methods: Plasma levels of testosterone (T), androstenedione (A), and dehydroepiandrosterone sulphate (DHEAS) were measured in 15 boys with a conduct disorder (CD) and 25 normal control (NC) boys. Parents and teachers of the children rated the intensity of aggression and delinquency over the last 6 months. Results: CD boys had significantly higher levels of DHEAS and marginally significantly higher levels of A; there were no differences in T. Moreover, DHEAS levels were significantly positively correlated with the intensity of aggression and delinquency as rated by both parents and teachers. Conclusions: The results suggest that adrenal androgen functioning plays an important role in the onset and maintenance, of aggression in young boys.