Sleep disorders are quite common in adolescents and sleep disturbances occur most often during the mid-adolescent years. These disorders result in considerable negative consequences in terms of increased accidents, decreased academic performance, and increased behavioral difficulties. Over the past 25 years, the evaluation, diagnosis, and treatment of sleep-related breathing disorders has undergone dramatic changes. The diagnosis and treatment of pediatric sleep disorders are now the focus of more complex and collaborative research efforts. This article discusses the differences between childhood and adolescent sleep cycles, delayed sleep phase syndrome, sleep-related breathing disorders, narcolepsy, parasomnias, and behavior-related sleep problems.