Children with epilepsy have high rates of sleep problems. Melatonin has been advocated in treatment of sleep disorders, and its beneficial effect has been confirmed in insomnia. The aim of this study was to assess melatonin levels in children with intractable epilepsy and its relation to pattern of sleep and characteristics of seizure disorder, as well as the effect of melatonin therapy on those parameters. The study was conducted on 23 children with intractable epilepsy and 14 children with controlled seizures. Patients were evaluated by psychometric sleep assessment and assay of diurnal and nocturnal melatonin levels. Children with intractable epilepsy received oral melatonin before bedtime. They were reassessed after 3 months. Children with intractable epilepsy had higher scores for each category of sleep walking, forcible teeth grinding, and sleep apnea. At the end of therapeutic trial, patients with intractable epilepsy exhibited significant improvement in bedtime resistance, sleep duration, sleep latency, frequent nocturnal arousals, sleep walking, excessive daytime sleepiness, nocturnal enuresis, forcible teeth grinding, sleep apnea, and Epworth sleepiness scores. There was also significant reduction in seizure severity. Thus, use of melatonin in patients with intractable seizures was associated with improvement of both many sleep-related phenomena and the severity of seizures.