Arsenic is an environmental toxicant with a worldwide distribution that causes neuropathy, skin and vascular lesions and leads to cancer in chronic exposure. While arsenic concentration is extremely high in drinking water due to its high level in the earth’s crust in some areas, major causes of arsenic contamination are mining and smelting industries. The aim of this study was to determine the amount of arsenic and some blood parameters including total protein, AST (Aspartate Aminotransferase) and ALT (Alanine Aminotransferase) activity in sheep flocks grazing around two neighbour smelting centres of gold mines and their tailing dams located in Takab, West Azerbaijan province, Iran. The samples of wool and blood were collected randomly from 54 (46 female and 8 male) sheep in 4 villages surrounding the area. Results showed that arsenic concentration in the wool taken from exposed animals in this area was apparently higher than normal range (Mean values are more than 40 mg/kg comparing to the normal amount that is 5-10 mg/kg). The mean values measured for AST activity in the present study indicated the potential liver damage caused by chronic arsenic poisoning. However, there were no significant changes in ALT activity and total protein. Further large scale studies are suggested to confirm chronic arsenic toxicosis in sheep and other domestic animals.