There are few self-reports of impulsivity dealing with children, although this personality trait has been related to many behaviour problems in both children and adolescents. The appropriateness of the Dickman Impulsivity Inventory for Children (DII-c) and the Dickman Impulsivity Inventory (DII) to measure impulsivity in children and adolescents was assessed. The factorial structure of the DII-c and the internal consistencies for both inventories suggest the measured dimensions are not consistent until adulthood. These self-report measures are not appropriate for children and adolescents.