Any abnormal increase in the volume of a lower member may be defined as "swollen leg", whether it is general and segmentary, or partial and local. This work concentrates on swollen legs caused by primary varicose disorders and does not deal with obstructions in the deep venous trunks. Swollen leg due to varicose disorder is marked by huge varices in clusters with total avalvulation. This constitutes a "phantom" swollen leg, for the evidence disappears when the patient lies down. It usually involves the long saphenous vein. It can be treated efficiently by surgery or sclerotherapy. Swollen leg of chronic venous stasis is due to vesperal oedema of complex character. Saphena insufficiency is to be observed, sometimes of the long saphenous vein, but usually of the saphena parva. Eventually large leg becomes permanent. Diagnosis is often difficult in swollen legs of deep venous stasis, and required venous functional investigations. Acute and painful forms may closely resemble ambulatory phlebitis. In all cases, lymphoedema ought to be considered, and the bruise test is conclusive. Sclerotherapy of the dilated saphenous trunks is often enough. Elastic stocking compression is sometimes necessary in order to obtain the best results, in conjunction with phlebotonics and crenotherapy. Swollen, inflammed legs are of two types: --Superficial thromboses, whether varicose or not, may be revelatory of underlying thromboembolic, cancerous, or hemopathic disease. This is the case for ascending phlebitis of the great saphenous vein which carries the risk of embolus, hyperuricemia, and, in the most localized forms, a risk of focal infection. --Phlebitis of the small saphenous vein, while rare, may be mistakenly taken to be deep lep phlebitis. The swollen legs seen in varicose trophic disorders are characterized by infectious or inflammatory edema, hypodermitis, and often, an ulcer. They may take on all of the clinical aspects of post-phlebitic disease, but functional vein studies will demonstrate patency of deep vein trunks. Active treatment and careful follow-up of venous and tissular lesions as well as suppression of aggravating factors should result in healing.