The present study tested the antigenic relationship between the three Egyptian strain of Fasciola gigantica antigens; coproantigen, excretory-secretory and egg antigens, versus their related hyper-immune sera and select the most specific one. By using SDS-PAGE, a structural homology was demonstrated in F. gigantica ES and egg antigens. This homology was resided in the components of the similar molecular weights between both antigens. When no cross-reaction was recorded with the coproantigen, the intense cross-reaction occurred between ES and egg antigens in ELISA technique. This was attributed to the presence of common bands at 18.0, 20.4 and 27.6 KDa in between them. Consequently, the F. gigantica coproantigen and Copro HIS reflected the lowest level of the cross-reaction with the other evaluated F. gigantica antigens. The cross-reaction elucidated in the present study between the F. gigantica ES and egg antigens was mainly at the low serum dilutions. The distinction between the specific and the cross-reactive binding activities was clear ly marked with the highly diluted sera.