The study was conducted to examine 876 sheep of different ages and of both sexes in Basrah province, Iraq during September 2023 to March 2024. 180 animals with clinical signs of pneumonia and acute vital signs were included. Results showed that 160 (88.88%) samples out of 180 were sero-positive for indirect ELISA, However, the age group less than 6 months exhibited highly infection rate compared with sheep more than one year old. Moreover, all infected animals showed acute clinical manifestations including partial or complete loss of appetite, rapid and difficult breathing with abnormal lung sounds, where pleural frictional sound is the common type, nasal discharge, Pleurodynia, reproductive cough as well as a signs of anemia. Results of macroscopic appearance of carcasses show congested, lungs consolidation, hemorrhagic area and spots as well as hepatization. whereas, Histopathological results indicate, thickening of alveolar wall with hemorrhage in interlobular tissue and congested blood vessel. Moreover, hyperplasia with excessive inflammatory cells in alveolar lumen as well as bronchioles with necrotic area was also indicated beside interstitial pneumonia with exudate in bronchial lumen and hyperplasia in epithelium cells of bronchial tissues. It has been concluded that Mycoplasma ovipneumonia infection affected sheep hardly reflecting high morbidity and mortality rate and economic loses, therefor a fit control measure programmed should be planed.