We evaluate the 3-year result of 145 oral leukoplakias operated on by outpatient carbon dioxide laser surgery at the Istituto Nazionale Tumori, Milan, Italy. The surgical technique that was used consisted of excision in 140 patients and vaporization in 5 patients. Cancer was found in 14 out of 140 patients who underwent excision (10%). In the analysis of the disease-free survival rate and of the unfavorable pattern of events, only 131 patients with benign postoperative histologic diagnosis were considered. Fifty-eight patients developed unfavorable events. The probabilities of remaining free of disease or of developing local relapses or new lesions at 3-year survival was 0.57, 0.27, and 0.19, respectively. Two patients had oral carcinomas after the operation. Forty patients modified their alcohol or tobacco habits or their teeth and/or prosthesis. Moreover, only two patients modified these factors before the unfavorable events occurred.