In 337 limbs (208 patients) with primary varicose veins, Doppler ultrasound was used to detect reverse flow in the saphenous veins caused by manual compression of the calf. According to the extent of reverse flow in the saphenous trunks, varicosities of the long saphenous vein were classified into five types and the short saphenous vein, into four types. Two hundred five (66.3%) of 309 limbs with varicosities of the long saphenous vein had reverse flow in the entire saphenous trunk from the groin to the ankle. In varicosities of the short saphenous vein, 37 (52.9%) of 70 limbs showed reverse flow from the popliteal fossa to the ankle. The other limbs demonstrated reverse flow only in some segments of the saphenous veins. On the basis of these Doppler ultrasonic findings, selective stripping operations were performed on 80 limbs, in which only the segments with venous reverse flow were selectively removed. Postoperative plethysmographic measurement of the venous reflux volume and follow-up studies showed that results of the selective stripping operations were as satisfactory as those of the standard stripping operations (189 limbs) in which the entire saphenous vein was removed. Furthermore, the selective stripping operation was advantageous in reducing the incidence of nerve injury.