The present study was carried out on a total number of 78 bovine  (cows48- Buffaloes 30) The obtained sera were investigated for detection of brucella-antibody titer using serological tests Rose Bengal plate Test (RBPT), Tube agglutination test (TAT), indirect  ELISA (iELISA) and Complement Fixation Test (CFT). Abomasal content were collected from 78 aborted fetuses for bacteriological and Polymerase Chain Reaction (PCR) assays. The results of serological analysis revealed that the positive reactors were 60 (76.92 %), 55 (70.51 %), 58 (74.36 %) and 57 (73.08 %) using RBPT, TAT, iELISA and CFT, respectively. RBPT and iELISA tests showed the highest seropositivity. Meanwhile, the lowest ones were obtained by TAT and CFT tests. Brucellaem elitensis biovar3 was isolated from 31 out of 48cows (abomasal content) aborted fetuses and21 out of 30buffaloes (abomasal content) aborted fetuses. PCR assay for detection of Brucella in aborted fetuses were 33 out of 48 in cow and 22 out of 30 in buffaloes. Pathological examination in organs of aborted fetuses infected by Brucella melitensis showed significantly pathological lesions in lungs, liver, spleen and placenta. Immunohistochemistry revealed the presence of positive immunostaining brucella antigen in formalin-fixed, paraffin imbedded tissue sections of lung, liver, spleen, and placenta by using avidin–biotin complex peroxidase technique. Electron microscopical finding of lung, liver and spleen showed that the cytoplasm of neutrophil and macrophages containing dark bodies of cocobacilli. TEM of placenta revealed that the Trophoblasts filled with degenerated organisms.