The use of atypical antipsychotics in children began in 1992 with several small case series with clozapine. Since that time, five other atypical agents, risperidone, olanzapine, quetiapine, ziprasidone and aripiprazole have been introduced into the US market. The newer atypical agents are not associated with agranulocytosis that has limited the usefulness of clozapine. Among the atypical antipsychotics, risperidone has remained the most extensively studied in children and adolescents, for a variety of problems, including Tourette's disorder, conduct disorder, schizophrenia, aggression, and pervasive development disorder. Risperidone has been shown to be an effective treatment in many of these disorders. However, weight gain, hyperprolactinemia, and extrapyramidal symptoms (EPS) are troublesome adverse effects more commonly associated with risperidone such that the drug's utility in this aged patient population is limited. We expect that the utility of aripiprazole in treating the pediatric population will not be limited by adverse effects like the other atypical antipsychotics.