Two personal cases from the pretext for a short discussion on the syndrome defined by Cockett in 1965. The condition is a post-phlebitic syndrome localised to the left common iliac vein. This vein, which is crossed by the right common iliac artery, is in fact the site, at the level of this crossing, of intraluminal and extraluminal lesions whose nature and significance are controversial. The clinical manifestations are those of a severe post-phlebitic syndrome and the classical medical treatments are often inadequate. Surgery can bring about improvement, but its indications must be carefully assessed.