During the 3 years that the enzyme-linked immunoelectrotransfer blot (EITB) assay for the diagnosis of human cysticercosis has been in use at the Centers for Disease Control, 50 patients with both pathologically confirmed neurocysticercosis and computed tomographic (CT) or magnetic resonance imaging (MRI) scan results were identified. Of 32 patients with two or more lesions, 94% had detectable antibodies by EITB compared with 28% of 18 patients with single lesions. Patients with only calcified cysts (single or multiple) were less likely to have EITB-positive results than were those with noncalcified, enhancing lesions. Antibody was detectable more frequently in serum than in cerebrospinal fluid, regardless of the number or apparent condition of the cysts. These findings confirm that the EITB assay for cysticercosis antibodies is highly sensitive in patients with multiple, enhancing intracranial lesions but is less sensitive in patients with single lesions and in those with calcified lesions.