Twelve complete autopsies of patients with Argentine hemorrhagic fever were studied. The most significant findings were generalized hemorrhages, myocarditis, acidophilic bodies, and focal necrosis in the liver, papillary necrosis and hemorrhage in the kidneys, reticulum cell hyperplasia and erythrophagocytosis in the lymph nodes and erythroid hypoplasia of the bone marrow. These lesions were similar to those described in other hemorrhagic fevers of different parts of the world. The finding in three cases of intravascular fibrin thrombi together with the presence of the' clinical syndrome of disseminated intravascular coagulation suggests that intravascular clotting is responsible for some of the hemorrhagic phenomena of Argentine hemorrhagic fever.