Abstract: | Clostridium Chauvoei is an anaerobic, endospore forming gram-positive organism causing black quarter, a deadly disease of domestic animals. A total of 30 Swiss albino mice weighting between 18-20g were used for experiment. In this study, the bacterial load, pathological lesions and histopathological changes in heart, liver and thigh muscles of swiss albino mice caused by Clostridium Chauvoeiat1d.p.i, 2d.p.i, 3d.p.i, 4d.p.i and 5d.p.i (Days post infection) respectively investigated and it was observed that the bacterium Clostridium Chauvoei produced more severe pathological changes in heart, liver and thigh muscles respectively. Necrosis was observed in the tissues examined, both grossly and histopathologically. It is concluded from the present study that, Clostridium Chauvoei is potentially pathogenic and its play an important role in the mechanisms of blackleg in swiss albino mice, they can be particularly important to study its pathogenic characteristics.