The ulcus cruris is an ulcerative lesions caused by chronic venous stasis and chronic venous hypertension. Every pathologic obstacle to venous return can cause ulcus cruris. Ulcus could be brought back to 3 situations: postphlebitic syndrome, chronic venous insufficiency and primitive varicosities. The common denominator is always the increase in venous pressure, the appearance of reflux and venous stasis. Venous ulcers are possibly characterized by tissue degeneration and by bacterial superinfection. A particular bacterial flora is found in these injuries, it is qualitatively different from that of healthy skin. The therapy of ulcus cruris cannot leave out by its etiopathogenesis: the first treatment always consists in the stasis suppression to arrive quickly to a complete cicatricial would repair. In it three moments are recognizable: ulcus abstersion, disinfection and cicatrization. The venous ulcer is not cured when it is closed, but when it has no recurrency: the cicatrization is obtainable treating the principal causes, eliminating the venous stasis and anticipating the relapses.