In this investigation, presence of Mannheimia haemolytica and Pasteurella multocida in sheep brought to Kafkas University Faculty of Veterinary Medicine between 2011 and 2013 with a suspicion of pneumonia was studied by immunohistochemical and bacteriological methods. Study materials were 100 sheep lungs. After routine histopathological investigations lungs were immunohistochemically stained with antibodies prepared against both of the agents. In bacteriological investigations, tissue samples were inoculated into 7% sheep blood agar and Mc Conkey agar and incubated for 24-48 h in aerobic conditions, and the suspected colonies were evaluated for Mannheimia and Pasteurella species. In histological investigations, pneumonias were classified as 28% fibrinous bronchopneumonia, 21% prulent bronchopneumonia, 20% acute-catharal bronchopneumonia, 18% interstitial pneumonia, 11% verminous pneumonia and 2% adenomatous pneumonia. In bacteriological investigations Mannheimia haemolytica and Pasteurella multocida was detected in 19 and 3 cases, respectively, these numbers were 17 and 2, respectively in immunohistochemical investigations. The results of PCR analysis for both Mannheimia haemolytica and Pasteurella multocida paralleled with the findings of microbiological culture. The results of the study showed that Mannheimia haemolytica is an important cause of pneumonia in sheep in Kars, and Pasteurella multocida, although with lesser importance can cause pneumonia in this species.