Bacteriological and pathological examinations were carried out on 500 animals (336 cows and 164 buffaloes) slaughtered in two abattoirs in Ismailia Governorate. From these animals proper samples were collect­ed from lungs and bronchial lymph nodes. The bacteriological examina­tions revealed the infection of 65 cows (19.34%) and 31 buffaloes (18.90) with Staphylococcus aureus, Streptcoccus pneumoniae, Coryne­bacterium bovis, E. colt, Bacillus species, Pseudomonas aerginosa and mixed infection. The most predominant organism was Staph. aureus with percentage of 8.03% in cows and 7.92% in buffaloes in relation to the total examined cases. Cattarrhal bronchopneumonia was the characterstic feature of Staph. aureus infection. In Corynebacterium bovis infection the histo­pathological changes refered to chronic proliferative stromal pneumonia. In Pseudomonase aeruginosa infection, the examined lungs showed giant cell pneumonia. Other bacterial lung infections showed varied degrees of pneumonia. The examined lymph nodes revealed lymphoid depletion and oedema. Pathological lesions were similar in cows and buffaloes.