Fasciolosis caused by Fasciola gigantica is one of the major public health problems in the world including Egypt. Immunodiagnostic methods are more applicable for their better sensitivity and specificity than other methods. The present study was conducted to cysteine proteinase (CP) antigens of F. gigantica in IgG-ELISA to diagnose human fasciolosis. IgG-ELISA with 2 cysteine proteinases of 27 kDa (Fasl) and 29 kDa (Fas2), obtained from the regurgitated materials of adult worms, were evaluated using serum samples from 90 Egyptian patients infected with F. gigantica, 55 patients with other parasitic infections and 50 healthy volunteers. The diagnostic sensitivity and specificity of Fas1 for detection of F. gigantica infection were 91.1% and 89.1%, respectively. The positivity of the assay was 95%. The
positive and negative predicted values were 91% and 86%, respectively. These data suggest that IgG-ELISA with Fas1 is highly sensitive and specific assay and could be used for the immunodiagnosis of human fasciolosis.