This study was conducted on two flocks of sheep suffering from abortion in Mosul city, Iraq. The clinical findings in ewes were abortion during the 3-4 months of gestation period in the both flocks. The total percentage of abortion was 11.7 %, whereas stillbirth percentage was 4 %. Brucella spp. was isolated from four (33.3 %) of the 12 samples (stomach contents of the aborted fetuses). All culture – positive samples had also positive with direct smears. By a modified enzyme-linked immunosorbent assay (ELISA), Brucella antigens were detected in the fetal stomach contents of 5 samples. The sensitivity and specificity of the modified ELISA were 100 % and 87.5 % respectively. The test had a good negative predictive value but only a moderate positive predictive value. Therefore, the test would be useful for confirming the existence of suspect disease. Comparison of modified ELISA with bacterial isolation demonstrated a close agreement (Kappa value = 0.92). Of the 12 serum samples from aborted ewes, eight samples were positive with Rose Bengle test (66.7 %), more than 10 samples (83.3 %) were detected by indirect ELISA test.