A patient had fatal hypovolemic shock and edema. As in previously reported cases, the mechanism of shock appears to be loss of protein and fluid from the vascular bed. Extensive studies of all patients have revealed no cause for this extraordinary vascular permeability. Analysis of the reported cases suggests that subsequent patients with this syndrome should have analyses performed to determine the presence of vascular reactants such as kinins. A study of these cases suggests a method of treatment of similar episodes of hypovolemic shock. Observations from this case and the one previously reported from this center suggest that vasopressor agents such as catecholamines probably are contraindicated.