Cervical conization was performed m 198 patients of histologically proven CIN(Cervical Intraepithelial Neoplasm) grade III diagno with colpoacopically directed biopsy. They were colposcopically satisfactory group and selected during 9 yeers and from Janusry 1983 to September 1992 in the department of Obstetrics and Gynecology, Yonseii University College of medicine. The results of Fap smear, initial colposcopic impression and cone biopsy were compared, and so, necessity of cone biopsy in histologicallly proven CIN III patients diagnosed with colposcopically directed biopsy was evaluated. The results were as follows: 1. 113 of 198 cases(57.1%) of Pap smear were noted as abnormal finding but 48 of 198 cases (24.2%) were noted as normal Pap srnear finding. 37 cases(l8.7%) of patients didnt reeeive routine Psp smear. 2. Diagnostic aecuracy of initial colposcopic impression was 85.3%(169 or 198 cases) within 1 Jung Fil Lee, et al. : Is Cone Biopsy Really Neeessary in Cervical Intraepithelial Neoplasia Crade III Patients Diagnosed with Colposeopically Directed Bioysy histologic degree. 3. Under the consideration of 1 histologic degree, 97.5%(193 of 198 cases) of cone biopsy results reveal the same as those of colposcoyically directed biopsy. If the adequate patient. selection and biopsy was done by well trained colposcopist, it seemed that it was not necessary to perform cone biopsy after colposcoyieally diredcted biopsy in CIN III patients.