Problems of sleep initiation and maintenance occur in 15% to 25% of children and adolescents. Studies of the benefits of melatonin for sleep disorders have been published for healthy populations, for children and adolescents with attention-deficit hyperactivity disorder, for children and youth with autism, and for several other special populations. These studies demonstrate benefit with minimal side effects. However, all studies have involved small numbers of subjects and address only short-term use of melatonin. There are no good data concerning the safety and efficacy of long-term melatonin use. Further studies are needed to confirm the usefulness and safety of melatonin for sleep disorders in children and adolescents.