The American College of Phlebology Guidelines Committee performed a systematic review of the literature regarding the clinical impact and treatment of incompetent accessory saphenous veins. Using an accepted process for guideline developments, we developed a consensus opinion that patients with symptomatic incompetence of the accessory great saphenous veins (anterior and posterior accessory saphenous veins) be treated with endovenous thermal ablation (laser or radiofrequency) or ultrasound-guided foam sclerotherapy to eliminate symptomatology (Recommendation Grade 1C).