Normal and psychopathological patterns of behavior symptoms in pre-school children were described by a classification approach using cluster analysis. The behavior of 406 children, average age 4 years 9 months, from the general population was evaluated at home visits. Seven clusters were identified based on empirically defined dimensions: attention, hyperactivity, aggressiveness, social relationship problems, sleeping problems, eating problems, depression and anxiety. Clusters scoring high in inattention, hyperactivity, aggressiveness, and social relationship problems but low in depression and anxiety were found and could indicate early onset conduct disorder. The approach of analysing patterns of symptoms expands the basis on which normal and psychopathological patterns are distinguished.