Phlebography makes the diagnosis of lower limbs venous thrombosis possible, and points out as well both site and extension. The technique used is the "free flow" technique which is modified so as to visualize the iliac veins as well as inferior vena cava. The presence of lacunar image or cupula-shaped interruption demonstrates a recent thrombosis above all if associated with venous dilatation; absence of a main venous trunk and collateral circulation do demonstrate a previous thrombosis. Phlebography fails to explore easily some veins, especially pelvic and deep femoral veins, as well as to determine the clot initial appearance. Non-invasive methods, such as labelled fibrinogen, Doppler ultrasonography and rheoplethysmography are less sensitive and specific; only Doppler ultrasonography associated with ultrasound can supply quite good results. Despite such efficient methods, especially ultrasound combined with Doppler ultrasonography, phlebography appears as the main examination in the patients presenting with various thrombosis or pulmonary embolism.