Between 1977 and 1987, the CO2 laser was used to treat 4024 women who were diagnosed by cytology studies, colposcopy, and biopsy examination to have cervical intraepithelial neoplasia. On the basis of specific indications, these women were treated by vaporization, excisional conization, or combination conization procedure. The evolution of methodology for each laser technique was based on specific pathophysiology and long-term observation of results. A total of 3070 patients underwent vaporization, 2881 of whom had no evidence of disease after one laser exposure (93.8%). Of the 954 patients who had laser excisional procedures, 925 (97%) had no evidence of disease. The most common complications observed were intraoperative and postoperative bleeding; however, sutures were required in only 1.34% of the latter. The risks of cervical stenosis (1.1%), incompetent cervix (0%), and pelvic infection (0.05%) were very low. This 10-year study demonstrated that the CO2 laser was a highly effective method for treating cervical epithelial neoplasia and had the added benefit of preserving reproductive function and anatomic integrity.