Background:cystic echinococcosis (CE) is a complex, chronic and neglected disease caused by the larval stage of Echinococcus granulosus. The effects of this neglection have a powerful impact in remote rural areas whose population has no chances of being diagnosed and treated correctly without leaving their works and travelling long distances, sometimes taking days to reach the closest medical center. The present study was designed to evaluate the diagnostic efficacy of purified polyclonal antibody (PAbs) raised against Echinococcus granulosus 50 and 31 kD proteins for detection of circulating hydatid antigen using dot ELISA. Materials and methods: the previous proteins from sheep and camel lungs  was purified by ammonium sulfate and caprylic acid.The purified protein injected in  Newzealand rabbits to raise specific polyclonal antibodies (pAb) against E. granulosus. Detection of 50 and 31 kD proteins in serum by dot-ELISA gave a sensitivity of 92.9%, a specificity of 95%. Conclusion: dot-ELISA techniques emerge to be adequately sensitive assays for the diagnosis of human echinococcosis using cathepsin B antigen.