A technique for lateral subcutaneous internal sphincterotomy has been used in 300 patients. In 200, the blind method was used, and in 100, the open technique was used. Although the number of patients and the follow-up period were not matched, the early results were somewhat better with the group of patients who underwent the open technique than with those who underwent the blind procedure, particularly in regard to postoperative bleeding. We recommend this technique both to minimize bleeding and to afford the surgeon more technical control.