Abstract: Brucellosis is an infectious disease characterized by abortions in females and epididymitis and orchitis in males. There is paucity of information on the occurrence of brucellosis among small ruminants in Yabello district. Therefore, this study was designed with the aims to determine the prevalence and assess risk factors associated with the occurrence of brucellosis among small ruminants in the district. Seroprevalence study of small ruminant brucellosis in Yabello district was conducted from November 2009 to April 2010. Sera from 384 sheep and goat were tested by Rose Bengal Plate Test. Of 384 sera examined 9 (2.34%) were positive to RBPT. The sera screened positive by RBPT were retested using complement fixation test and among 9 sera samples tested 6 (1.56%) were positive for Brucella antibodies. The prevalence of brucellosis in this study among sheep and goats was found to be 1.17 and 1.88%, respectively. Small ruminant brucellosis among male and female animals was known to be 0.68 and 2.10%, respectively. Prevalence of small ruminant brucellosis in young animals was 0% while that of adult was 2.30%. Statistical analysis of the data showed that there was no significant difference in seroprevalence to Brucella antibodies and species, sex and age of the animals examined (p>0.05). The occurrence of brucellosis among small ruminants in Yabello district might pose productivity and reproductivity problem and will be a public health risk. Therefore, best control and prevention methods brucellosis among small ruminants need to be implemented.