The pathologies of the venous system are characterized by a relevant socioeconomic impact in western countries. To this regard, the blood flow correction allows to solve the most important venous pathologies. In these cases, in order to guarantee the restoration of normal blood flow by means of proper modifications of the venous network, the correct planning of haemodynamics surgical operations is needed; such planning in turn depends on the right analysis of the possible consequences of flow modification. To this end, a mathematical model, that allows to precisely study the physiological and pathological behaviour of the venous network of the lower limbs, has been developed. The final goal is to use this model as an instrument helpful to plan surgical operations and give guidelines for the design and the test of new artificial devices. As for the modelling processing, a lumped parameters model has been derived with a resolution which allows to take into account the anatomic characteristics of the venous system.