The current study aims to isolate and identify M. haemolytica from ewes with clinical mastitis using conventional techniques with comparative study to their resistance to several types of antibiotics for the isolated bacteria from udder. The study was carried out in different regions of Nineveh governorate. Two Hundred sixty-six samples (133 milk samples and 133 udder skin swabs) were collected During December 2020, after the clinical examinations of the flocks. The samples were put in test tubes containing Brain Heart Infusion (BHI) Broth; then transferred into the Veterinary Public Health Laboratory, College of Veterinary Medicine, University of Mosul for different bacteriological, biochemical examination and sensitivity tests. The results showed that there is a matching between bacterial isolation ratios of milk and udder skin swabs of sheep affected by clinical mastitis at 51.12%. The results also showed a difference in the sensitivity test between M. haemolytica isolated from milk and skin swabs. It can be concluded that, the improper and indiscriminate use of veterinary medicines is one of the most important causes for the increase in bacterial resistance to antibiotics in treated cases without consulting a veterinarian.