While occlusion of the inferior vena cava below the level of the renal veins, either iatrogenically or pathologically acquired, is a common occurrence today, obstruction above the renal veins has been considered to be relatively rare. However, this condition may be more common than has been heretofore recognized. The latter situation, moreover, is not necessarily fatal as universally believed at one time. The fact that complete occlusion of the vena cava can be present and yet unsuspected is demonstrated by the two cases in our experience. Only scattered reports have appeared in the literature concerning this problem. Although thrombosis appears to be the most common cause of obstruction at this high level, many of the earlier reports dealt with occlusion secondary to trauma. Shuttuck 1 in 1913 reported one case that developed the nephrotic syndrome as a result of trauma to the inferior vena cava. This patient lived for 25