One hundred and one patients with poor results from the operative treatment of varicose veins were studied in an effort to determine the cause of the surgical failure. In a large majority, reoperation revealed that the primary cause of the poor result was the improper performance of the original operation. A smaller number of failures were due to errors in selecting the operative procedure. Relatively few poor results in long-term follow-up were attributable to the congenital predisposition to varicosity. When operation is properly planned and executed, it produces better long-term results than the injection compression therapy of varicose veins.