Serum samples from sequential patients who underwent cerebral computed axial tomography (CT) scan in a Peruvian radiologic clinic were tested by the highly sensitive and specific enzyme-linked immunoelectrotransfer blot (EITB) test to detect antibodies to Taenia solium. The results of the EITB test were compared with those obtained by CT scan for the diagnosis of neurocysticercosis. Of the 383 patients sampled, 32 (8%) were seropositive. The results of CT and EITB were frequently discrepant. When compared with the EITB assay, the CT scan was 44% sensitive and 95% specific. The sensitivity of CT increased to 63% if less specific images (single calcifications, granulomas, or hydrocephalus) were included. The CT scan for diagnosis of cysticercosis can best be used in conjunction with a reliable serologic test such as the EITB.