Objective: The aim of this study was to assess the anatomic variations of the sapheno-femoral junction (SFJ) and its incidence. Patients and Methods: Between April 2005 and March 2010, 2,552 limbs of 1,563 patients with complaints of varicose veins underwent ultrasonography. Ultrasonography was used to identify the anatomical variation of the SFJ, especially the relationship to the femoral artery. Results: Variations were seen in 6 limbs (0.24%) at the SFJ. The most common anatomical variation was the great saphenous vein crossing posterior to the common femoral artery, which was present in 3 limbs. Conclusions: It is important to investigate the anomaly of the SFJ using preoperative duplex ultrasound, although its incidence is lower than that of the sapheno-popliteal junction. The anomaly of the SFJ always should be taken into consideration in order to minimize surgical complications of varicose veins.