Neurocysticercosis is the most common cause of acquired seizures worldwide. Most cases of this larval stage infection of the pork tapeworm Taenia solium occur in the developing world, although increasing numbers of cases are being recognized in the United States, particularly among Hispanic immigrants. The ability of the pathogen to persist for years within the host is the subject of immunologic and biochemical investigation. The major presenting symptom is seizures, although symptoms of obstructive hydrocephalus occur if cysts are located near the ventricles or in the subarachnoid spaces. Diagnosis is dependent on clinical, radiologic, and serologic data. Therapy with antiparasitic agents, especially albendazole, is effective in large burden disease or disease within sensitive neuraxis sites (the ventricles, the subarachnoid spaces). When patients with radiologically enhancing disease are given cysticidal therapy, there appears to be a reduction in seizure recurrences. Surgery is indicated for disease in selected anatomic sites. Longterm prevention requires attention to pork husbandry and general sanitation, including the potential use of mass human chemotherapy and porcine vaccination.