The scope of the problem in regard to childhood aggression or conduct disorders is large and far exceeds the resources for dealing with them. Moreover, such children are at high risk for developing serious adolescent and adult psychological problems. Nurse practitioners are placed in strategic positions to be able to screen for, identify and treat early signs of conduct disorders in young children. This review describes assessment procedures and the essential components of a parent training program designed to help families reduce childhood aggression. By intervening with families early, nurse practitioners may be able to design effective preventive programs and improve the prognosis for these children.