One hundred and sixty-eight cases of cervical conization were performed for cervical intraepithelial neoplasia (CIN) in a 32-month study. The indications for conization were unsatisfactory colposcopic finding, abnormal epithelium that extended into the endocervical canal, a microinvasive cervical cancer, and significant discrepancy among cytology, colposcopy, and/or punch biopsy histology. In the early period of the study, conization was done by the cold-knife method (N = 107), whereas loop diathermy was used in the latter part of the study (N = 61). Both groups were similar in terms of age, indications for conization, and size of cervical cone specimens. Loop diathermy conization was done in a significantly shorter time (5.7 +/- 1.8 minute vs 15.2 +/- 6.1 minute)(P < 0.05) than cold-knife conization. However, the difference in the postoperative complications between loop diathermy(3.0%) and cold-knife conization(4.7%) was not significant. The incidence rate of residual CIN III lesions in the subsequent hysterectomy specimens, found by histological documentation on these specimens was 25.0 and 26.1 percent after loop diathermy and cold-knife conization respectively. These results suggest that loop diathermy is much easier to perform and a more time-conserving treatment modality than cold-knife conization in the management of patients with cervical intraepithelial neoplasia.