Hydatid cyst is an important and zoonotic infection caused by cystic stage of Echinococcus granulosus. It is a major and economic problem in most areas of the world that livestock are kept such as Iran. In this study, a total of 111 buffalo,s sera from Center of Buffalo Sperm Preparation (CBSP), Orumia (West Azarbayjan province, Iran, 2003) were examined for the presence of hydatidosis by using enzyme-linked immunosorbent assay (ELISA). 5 μg protein per mL of antigen B from sheep hydatid cyst fluid was used in this assay. Optimum dilution for rabbit anti-bovine peroxidase conjugate (Sigma) was used 1:5000. Overall results indicated 32.4% of serum samples positive for hydatidosis. Results indicate buffalo is sensitive intermediate host for Echinococcus granulosus in this province.