The author reports a case of cerebral cysticercosis with predominance of psychiatric symptoms and with convulsions treated with sulfadiazine. This drug has been used, but as yet its usage is not well established. With this treatment there was marked improvement of the clinical symptoms and decrease of the abnormalities found in the cerebrospinal fluid test. This publication is justified by the good results obtained with this drug in the treatment of cysticercosis, a disease relatively frequent among us.