To assess the efficacy of colposcopy-direct.ed cervical conization(CCC), compared with that of naked-eye conization(NCC), in the management of cervical intraepithelial neoplasia(CIN), 286 patients with punch-biopsy proven CINs who underwent either CCC or NCC from 1985 to 1988 were evaluated. The incidence of residual grade lll CIN 1esi6ns in the specimens from hysterectomies perforrned in the presence of histologic documentation of CIN 1g in cervical tissues obtained from CCC, and NCC was 22.6(20/92) and 42.4(25/59) percent respectively(p<0.05). Morbidity after post conization hysterectomy was 7,2 and 20.0 percent with the interval between conization and hysterectomy less than 48 hours, and more than 6 weeks respectively; these were significantly lower than 48.8, 50, 57.1 percents noted interval between 48 hours and 6 weeks(p<0.05). The difference in morbidity was not influenced by the type ot conization. It can thus be concluded that CCC, compared with NCC, allows a fairly accurate assessment of the CIN lesions, especially in delineating the lesions periphery and extension into inner columnar cells aiding in biopsing the tissue of optimum size into inner columnar cells aiding in biopsing the tissue of optimum size and shape, diminishing the incidenee of residual lesions, and that extrafascial hysterectomy appears to be an appropriate mode of surgery for CIN III.