Although the scientific evidence is not entirely supportive, atypical antipsychotics have been used widely for the treatment of children and adolescents with mental illnesses as alternatives to typical antipsychotics which have more serious unwanted adverse effects than atypical neuroleptics. On the basis of clinical experiences and research data, atypical antipsychotics have been prescribed for adolescents with schizophrenia, manic or mixed episodes of bipolar disorders, tic disorders, aberrant behaviors in pervasive developmental disorders, and impulsive or violent behaviors in disruptive behavior disorders. Due to their efficacy and relatively more tolerable side effects, the use of atypical antipsychotics has become increasingly popular in child and adolescent psychiatry. However, we should pay attention to the limitations associated with short-term clinical experiences and the lack of well-designed controlled studies, especially in terms of adverse effects including those involving metabolic processes.