The use of pharmacotherapy for children and adolescents with mental disorders varies widely across countries. More than 80% of the world use of stimulant medications occurs in the USA. The use of antidepressants and antipsychotics is many times greater in the USA than in other countries. Factors likely to influence the pediatric use of psychotropic medications are here examined and discussed. Variability in use reflects differences in diagnostic systems, clinical practice guidelines, drug regulation, health services organization, availability and allocation of financial resources, and cultural attitudes towards childhood behavioral and emotional disturbances. Cultural context seems to exert a greater influence on the identification and management of psychiatric disorders than on other areas of medicine. It is currently unknown if the heterogeneity in treatment approaches results in differential clinical outcomes and prognosis. A better understanding of the factors underlying international variability may help clarify the process of diagnosis and treatment selection in child and adolescent psychiatry.