In one fattening buffalo farm at Salhia, Ismailia Governorate 227 out of 5085 buffalo- calves showed clinical manifestations similar to Foot and Mouth Disease (FMD). The causative agent incriminated in this prob lem was FMD virus type "O". The virus caused oral lesions manifested as vesicles, erosions and ulcers inlips and dorsum of the tongue. The pathological studies revealed presence of bronchopneumonia, hepatitis, glomerulonephritis and myocarditis. These pathological lesions were illustrat ed and fully discussed.