AbstractThis survey was carried out to determine the infection rate of Coenurus cerebralis in Urmiaabattoir, West Azerbaijan, Iran. A total of 402 sheep heads were examined and the number ofC. cerebralis cysts per each head was recorded. Thirty three sheep heads were examined eachmonth during 12 months from 2006 to 2007. Of 402 heads, a number of 75 heads (18.65%)were infected with C. cerebralis. The cysts located in the left and right hemispheres andcerebellum were 54.63%, 40.20% and 5.15%, respectively. The infected heads contained 1-4cysts. The highest and lowest prevalence were detected in sheep in March (42.42%) and in July(2.94%), respectively. The infection rates according to age of sheep were 42.02% in 0.5 to 2years, 22.50% in 2 to 4 years and 8.92% in older than 4 years. The age specific infection ratesamong age groups were significantly differed (P < 0.05). Infection rate in Haraki breed(27.77%) was higher comparing to the rate in the Ghezel breed (21.13%) and Makoie breed(23.91%). However differences between sheep breeds were not statistically significant (P > 0.05)