Stroke is the single, most common cause of seizures in adults, especially in the elderly. Tumors account for many patients who present with seizures at between 25 and 64 years of age, but should also be excluded as a cause for seizures in children and the elderly. Cysts and vascular malformations have been identified increasingly as important causes for epilepsy. The incidence of seizures, pathogenesis, and seizure control achieved as a result of medical or surgical interventions are discussed for these four categories of structural lesions.