This study was conducted for isolation and identification of the pathogenic bacteria presented in the genital tract infection of the Arabian mares, and shows the anti microbial sensitivity. The study included 75 samples taken from infected mares suffering from genital tract infection diagnosed on the basis of case history and clinical signs which included bloody purulent discharge ranched from yellow to green in colure, fetid oder with congested and oedematous vagina and from some abortion cases, and from mares suffered from tetanus disease symptoms during the period between October 2007 to April 2008 in stud farms breeding mares in Mosul. The samples were collected by swabs from the clitoris, clitorial fossa and the vagina. Isolation of bacteria was performed using aerobic and anaerobic culture techniques. Results of the present study showed a total of isolation 75% from all samples taken with a high percentage isolation of Clostridium tetani (16.6%), followed by Archanobacterium pyogenes (10.6%), and Pseudomonas aeruginosa (8%), (6.7%) for each Enterobacter aerogenes, Klebsiella pneumonia, Streptococcus dysagalactiae subsp equisimilis, and (5.3%) for each bacteria Actinobacillus equilli, Streptococcus zooepidemicus, Staphylococcus aureus, then Proteus vulgaris (2.6%), and Escherichia coli (1.3%). The most bacterial isolates were resistant to amoxicillin (100%), ampicillin (90.9 %), and erythromycin (65.9%), while the most isolates were sensitive to kanamycin (70.4%). It could be concluted that the most important bacteria causing genital tract infection of mares could be Clostridium tetani and Archanobacterium pyogenes, Pseudomonas aeruginosa. The most bacterial isolates were resistant to amoxicillin, ampicillin and erythromycin.