Abstract: The present paper reports the protoscolicidal action of hydrastine, ether-acetic acid-1 ethanol admixture, H2O2, pyquiton and albendazole through in vitro or in vivo exposue, for 15 minutes and transplantation studies. The mortality of protoscblices in vitro and in vivo were 70.2% and 68.9% for 0.3% hydrastine, 56.8% and 56.2% for 10% ether-acetic acid-ethanol admixture, 6.0% and 8.8% for0.3% H2O2; 6.1% for 0.004% pyquiton in vitro and 5.0% were 10% and 25% for 0.3% hydrastine, 30% and for 0.004% albendazole in vitro. The survival rates after transplantation of protoscolices 37.5% for 10% ether-acetic acid-ethanol admixture, 100% and 95% for 0.3% H2O2 respectively. Disruption of external plasma membrane, hook detachment, sucker deformitv of protoscolices exposed to hydrastine were demonstrated by scanning electron microscopy. It is suggested that hydrastine exerts a profound intracellular effect on the protoscolex of E. granulosus of sheep and man, and might be a promising protoscolicide as adjuvant to hydatid surgery.