Sleep disorders occur commonly in patients with epilepsy, and can be responsible for symptoms of daytime somnolence and also can contribute to the intractability of epilepsy. The most important aspect of treating sleep disorders, especially sleep apnea, is the recognition of the problem. In a busy clinical practice, symptoms of sleep disorders are frequently overlooked or mistaken. Whenever sleep disruption or excessive daytime somnolence is potentially problematic, the patient should be referred to a sleep specialist and, if indicated, diagnostic testing performed (usually polysomnography with or without multiple sleep latency tests). The author also recommends that all patients receive basic counseling about sleep hygiene, because its principles are often helpful to patients in general. Even in the absence of a sleep disorder, the choice of an anticonvulsant can be partly tailored to the sleep needs of the patient, with alerting drugs (lamotrigine and felbamate) dosed early in the day and relatively sedating agents (phenobarbital and phenytoin) dosed later or at bedtime.