The role of pharmacologic agents in the treatment of learning and behavior disorders in children is discussed with respect to the biological basis of these disorders. Illustrative studies dealing with autonomic reactivity and cortical excitability as reflected in the cortical evoked response are presented. The question of the combined effects of drug and behavioral or educational therapies is considered. The author makes a plea for a comprehensive theoretical viewpoint in the consideration of learning and behavior disorders, not neglecting the biologic contributions of these problems and the possible benefits of combining environmental and pharmacologic treatments. (Author)