The study was conducted on 126 cattle (94 females and 32 males) of different ages (1->5 years) randomly selected from July 2007 to August 2008 in Mosul. Indirect ELISA test and other traditional tests (rose Bengal test, tube agglutination test and 2- mercapto-ethanol test) were used to determine the incidence of bovine brucellosis. The highest incidence of disease was recorded by Indirect ELISA, 23.01%, whereas it was 18.25%, 11.90% and 4.76% by rose Bengal, tube agglutination and 2- Mercapto-ethanol tests, respectively. The highest incidence was in females in all serological tests and the highest incidence was in females at the age between 1-3 years whereas in males more than 3 years of age it was 23.07%. The results of tube agglutination test revealed the titer 1/40 occurred mostly compared with other titers. Six chronic cases were determined by 2-mercapto-ethanol test. The degree of agreement of negative samples with rose Bengal test and indirect ELISA, tube agglutination, and 2- mercapto-ethanol tests was 94.17%, 100% and 100%, respectively, and by indirect ELISA with rose Bengal, tube agglutination and 2-mercapto-ethanol tests was 79.31%, 51.72% and 20.68%, respectively.