The efficacy of a multisystem and multicomponent treatment for children with a Conduct Disorder or Oppositional Defiant Disorder diagnosis is documented. Multi-component treatments usually includes psychotherapy for child and parent training. The purpose of this work is to examine the opportunity of effectuate this type of intervention in group setting. The present study consider 99 outpatients children, that have concluded three different types of treatment: one multimodal in group setting (Coping Power Program), one multimodal in individual setting, one unimodal. Results indicated that Coping Power Program produced relatively lower rates of externalizing behaviors at post-treatment evaluation. Are discussed possible clinics and etiopathogenetics implication of this results.