The absence of the inferior vena cava is a rare congenital malformation that could involve different segments of this vein: the reason of this miscellaneousness of prestations resides in its complex embriological formation. It's besides frequent the association with other malformations, cardiac or urologic. The Autbors describe a case of absence of the in-termediary pull of inferior vena cava, associate to Fallot disease. The clinical picture is currently represented trom tbe presence of a collateral abdominal circle; there is no evidence - also at the examination with eco-color-Doppler - of other important alterations, morphological and functional, of other segments of the venous system. However it is necessary - according to the Authors - an accurate outline of the venous chronic insufficiency, that must be realized beyond that with an adequate leg compression, also with the choice of an adequate physical activity.