The study included clinical investigation on pneumonia that caused by Mannheimia haemolytica (M. haemolytica) in sheep of Basrah Province, also isolation and identification were done and confirmed the diagnosis by PCR technology. The blood samples and nasal swabs were collected from 410 local sheep breeds of both sexes, and different ages. The results showed that from 410 sheep there were 25 healthy against clinical and cultural tests, which concerned as control group. The rest 385 sheep were revealed clinical pneumonia. The most important pneumonic signs included coughing, fever, abnormal lung sounds, dyspnoea, depression, mucopurulent nasal discharge as well as loss of appetite and separated from the herd. The laboratory bacterial culture and biochemical tests for samples from 385 pneumonic sheep appeared M. haemolytica in 81 (21 %) cases, which characterised by moist, round, white or grey colony with β-type haemolysis on blood agar. On MacConkey agar showed pink-red pinpoint colonies. While when stained by gram stain appeared as pink, short rods or coccobacilli and bipolar in methylene blue stain. The biochemical reactions included negative indole, urease and citrate whereas positive for oxidase and catalase tests. The PCR technique indicated that from 81 isolates there were 48 59, 2% cases had evidence by Rpt2 gen as M. haemolytica in local sheep of Basrah Province.