The author's preferred treatment for spider veins is sclerotherapy, a technique that uses irritants to obliterate the vessel lumen. She reserves laser treatment for vessels too small to sclerose, matting, and patients who refuse sclerotherapy. Treatment is initiated only after ruling out reflux in the larger superficial venous systems or through the perforators. For long lasting and satisfying results, the author recommends multiple treatments, using the lowest concentration of the most effective sclerosant to achieve vessel obliteration with minimal thrombus formation. She presents a guide to pretreatment evaluation, sclerosing solutions, injection technique, and posttreatment care.