Melatonin, which is used to treat sleep disorders, has anticonvulsant properties. The authors measured salivary melatonin and cortisol, at baseline and following seizures, in patients with intractable temporal lobe epilepsy and controls. Melatonin was reduced in patients with epilepsy at baseline compared with controls, and increased threefold following seizures. Cortisol also increased following seizures. Patients with intractable epilepsy have low baseline melatonin levels that increase dramatically following seizures.