The study aim was to quantify melatonin-associated improvement in sleep by means of a parent-completed sleep diary during routine outpatient activity. An investigation into sleep disturbance was made at neurology outpatient appointments. Those parents who identified a problem were asked to complete a sleep diary, after which treatment was initiated. The first week of the diary was completed before treatment, the second when established on the maximum dose of melatonin required. Forty-nine patients (26 males, 23 females) aged from one to 13 years, were treated between 1997 and 1998: 28 of these returned interpretable diaries. In a further 18 patients, an assessment could be made of the usefulness of the treatment. Patients were fairly typical of those attending a tertiary centre, the most common primary diagnosis being epilepsy (n=26). Only seven patients were visually impaired. Of the 46 patients who were assessed, 34 showed an improvement. No adverse effects were attributed to the treatment.