Our knowledge of the so-called incompetent leg perforating veins remains questionable. Anatomic and hemodynamic studies show that perforators in a healthy subject do not always convey inward flowing blood. Are incompetent perforating veins more frequent with increasing severity of chronic venous disease? Answering this question is difficult as no consensus has been established on how to assess incompetent leg perforating veins and we have no gold standard to refer to. The number of incompetent leg perforating veins is generally greater in severe chronic venous disease although their frequency in clinical stage 4 to 6 (CEAP classification) is not statistically different. This means that incompetent leg perforating veins are not markers of severity of chronic venous insufficiency. When analyzing published series which take into account etiology (primary or secondary venous diseases) the frequency of incompetent perforating veins is variable. Is surgical management required when incompetent leg perforating veins are present? Angiologists and surgeons have not come to an agreement on this point. What can be recommended today? It is generally accepted that the more severe the disease the more worthwhile surgical treatment. Technically speaking, subfascial endoscopic ligature is a promising new method although long-term results are still lacking. We must watch carefully the prospective and randomized studies which have been started in different countries. A lot of questions, only a few reliable answers.