Using the Doppler, we have studied the venous pressure, with the patients standing, of 6,172 legs. In a normal subject, the index of average pressure is 59 mmHg in the posterior tibial vein, and 58 mmHg in the long saphenous vein. Where there are varicose veins, the average pressure is 90 and 96 mmHg in the deep veins and in the superficial veins. In the case of post-phlebitic syndrome, the average index is 101 and 102 mmHg in the deep and superficial veins. In this work, the credibility of the method is discussed, and in particular, in comparison with the surgical methods, and its usefulness in current phlebological practice is defined.