The literature devoted to juvenile-onset bipolar disorder has rapidly expanded in the past 5 years with an emphasis on new concepts of prevalence and comorbid conditions. In the process of enlarging the knowledge base about the phenomenology of juvenile-onset bipolar disorder, this new literature has generated considerable controversy but has provided little information about pharmacotherapy. In the following case series, carbamazepine appeared to be a safe and effective treatment for juvenile-onset bipolar disorder. Controlled studies are necessary before any definitive conclusions can be reached about the efficacy of carbamazepine in the treatment of this form of bipolar disorder.