Extensive and severe myocardial lesions are reported in a patient who died due to snakebite (Crotalus Durissus Terrificus). These lesions are documented by clinical, electrocardiographic, enzymatic and histological evidences. The main pathological features are represented by sarcoplasmatic vacuoles, densely clumped myofibrils and amorphous acidophilic mass into the cardiac fibers. These lesions are identical to those which have already been described in skeletal muscle after snakebite. This seems to be the first case report that shows undoubt myocardial lesions due to snakebite with anatomopathological documentation.