Two groups of patients, 37 with primary basal cell carcinoma of the eyelid and 16 with basal cell carcinoma of the eyelid previously treated by other physicians were reviewed. All of the tumors were excised with at least 3 to 4 mm of normal-appearing tissue at each margin of resection. All of the excised specimens were submitted for frozen section studies of the margins. A total of 20 (54.04%) of the previously untreated tumors and eight of the previously treated tumors had at least one margin involved with tumor cells. Repeated excisions under frozen section control were done until all of the margins were free of tumor cells. To date, none of the patients treated in this manner had a recurrence of the tumor.