The existence of bipolar disorder in adolescents is now clearly established. However, whether bipolarity exists in children is more controversial. We reviewed the literature on acute and prophylactic treatment of bipolar disorder in youths. The guidelines for the treatment of bipolar disorder in children and adolescents are generally similar to those applied in adult practice. But no evidence-based data support the use of mood stabilisers or antipsychotics since we only found two placebo-randomised controlled trials testing the efficacy of lithium in the paediatric literature. Therefore, we support the view that prescriptions should be limited to the most typical cases. In fact, the use of mood stabilisers or antipsychotics in the treatment of bipolar disorder in children and adolescents appears to be of limited use when a comorbid condition, such as attention deficit hyperactivity disorder, occurs unless aggressive behaviour is the target symptom.