The hemorrhagic, necrotic and edematous effects observed in a 23-year-old patient from Lagunetica, Los Teques, state of Miranda, Venezuela, that was bitten by a commom Venezuelan rattlesnake (Crotalus durissus cumanensi), were described. The patient was treated with polyvalente serum, antibiotics and autograft. This finding allows to suggest that the poison of some Venezuelan common rattlesnakes has a systemic effect on the skeletal muscle and on capillaries that generate edema, hemorragic phenomena and necrosis