The Authors evaluated the use of antigens from Cysticercus cellulosae in the immunodiagnosis of human cysticercosis by haemagglutination test. The extract prepared from the es-colex and its chromatographic peak II were more specific than those from whole larvae, vesicular liquid and membrane antigens. Using sera from patients with parasitologically proven cysticercosis, positive reactions were obtained with a sensitivity index of 0.80 for escolex antigen and 0.84 escolex peak II antigen. Specificity of 1.0 was obtained for sera diluted at 1:8 for ES and 1:16 for ES II antigens.