Ninety-eight legs in 73 patients were evaluated with image-directed Doppler ultrasound for suspected chronic venous insufficiency. Examinations of the entire venous system were performed to determine lumen patency and valvular competence. Reflux during Valsalva maneuver in the femoral and great saphenous vein, and, after release of distal compression in the popliteal vein, indicated valvular incompetence. Twenty limbs had normal veins; Baker's cysts were found in three. Superficial venous insufficiency was found in 25 cases. Deep reflux, either alone or in combination with superficial reflux, was the predominant pathological feature (53 legs). Photoplethysmographic studies of the veins were performed on 24 limbs. Image-directed Doppler ultrasound was more successful in defining the exact site of venous incompetence and in detecting nonvenous pathology. By the combination of real-time imaging of the vein with gated Doppler sonography of flow, image-directed Doppler sonography is becoming the method of choice for the investigation of chronic venous insufficiency.