By means of parental questionnaires, sleep disturbances were assessed in 79 schoolchildren with epilepsy (mean age 10.12, range 5-16 years) for comparisons with 73 healthy control children matched for gender and to within a maximum of 6 months of age. The daytime behaviour of the children with epilepsy was also assessed by questionnaire. The children with epilepsy were considered representative of such children under general paediatric care. Sleep disturbance was classified into five basic types (poor quality sleep, anxieties about sleep, disturbances during sleep, symptoms of disordered breathing during sleep and short duration sleep) and the behaviour questionnaire provided scores on five factors (conduct problems, hyperactivity, attention problems, anxiety and physical complaints). Compared with normal controls children with epilepsy showed much higher rates of sleep disorders, particularly poor quality sleep and anxieties about sleep. In children aged 5-11 years associations were found between disturbed daytime behaviour and sleep problems, particularly poor quality sleep. There was also a significant association between seizure frequency and anxieties about sleeping. This study highlights the potentially serious psychological and other developmental implications of persistent sleep disturbance to children with epilepsy, and the need for further research on specific types of epilepsy with careful identification of the nature of both sleep disturbance and related psychological dysfunction.