Adventitial cystic disease (ACD) of the veins is a rare vascular disease. Most cases of venous ACD are located adjacent to the joint area, such as the common femoral, external iliac, and popliteal veins. To the best of our knowledge, 67 cases of venous ACD have been reported, and ACD of the superficial femoral vein (SFV) has never been reported. Herein, we report the case of a 57-year-old male who presented with swelling and discomfort in the left leg. Computed tomography venography revealed multiple cystic lesions in the left distal SFV. The patient underwent cyst excision, which relieved the compression in the vein, although mild stenosis prevailed in the SFV. After a week, thrombosis developed in the popliteal vein. The thrombosis resolved after three months of anticoagulant therapy, and the patient showed no recurrence of ACD during three years of follow-up.