Over the past decade, there has been greater acceptance of the existence of bipolar disorder (BD) in adolescents. The onset of BD during this period severely affects the acquisition of key developmental skills. Debate around diagnosis, comorbidity and treatment is strong and little is known about the long-term impact BD has on an adolescents as they approach adulthood, from both illness and functional perspectives. A review of psychological and medical databases using the search terms "adolescent onset", "pediatric onset", "juvenile onset", "bipolar disorder", "course" and "outcome" was conducted. Emphasis was placed on the information available from studies, which have described the outcome of adolescent onset BD either prospectively, retrospectively, or both. Twelve studies were identified that focused on the long-term course of adolescent onset BD. Findings on the course and outcomes are conflicting. These studies are from few centres or research groups and have small sample sizes, varied methodologies and relatively brief follow-up durations. There are few studies available on the course and outcome of adolescent onset BD. Although there seems to be less controversy in this age group compared to the prepubertal age group, there remains a need for prospective studies of large systematically ascertained samples.