Pneumonic pasteurellosis is a multi-factorial respiratory disease of cattle and sheep caused by combination of etiologic agents; hence, reliable information is needed on the inventory of Pasteurella species or serotypes for optimum control of the disease. This study was conducted with the objectives of isolation and identification of Pasteurella organisms from cattle and sheep using conventional and molecular methods. Cross-sectional studies were carried out on pneumonic lungs collected from abattoirs and nasal swabs from cattle and sheep brought to Asella, Holota and Sheno veterinary clinics for various reasons. Twenty five percent, 26.5% and 23.5% of nasal swabs collected from Asella, Holota and Sheno, respectively yielded Pasteurella species. In all the study sites Mannheimia haemolytica was more frequently isolated than Pasteurella multocida and Bibersteinia trehalosi. The frequency of isolation of Pasteurella species is higher in young animals than adults (OR = 1.56; 95 % CI: 1.02, 2.38); in pneumonic animals than those with no signs of pneumonia (OR = 4.67; 95 % CI: 3.03, 7.19) and in animals under intensive management than those managed extensively (OR = 2.46; 95 % CI: 1.12, 5.39). From a total of 176 pneumonic lung samples (93 cattle and 83 sheep) collected and investigated Pasteurella species were isolated from 27.27 % (48) of them. Mannhemia haemolyitica is the predominant isolate from pneumonic lungs. Molecular characterization also confirmed the identity of P. multocida and M. haemolytica. In addition, the serovars of P. multocida isolates identified were A1 and A3. This study revealed that M. haemolytica, P. multocida and B. trehalosi are commonly circulating in cattle and sheep originated from various parts of the country. Besides, the serotypes of P. multocida identified are those known to cause pneumonia in ruminants.