20 years with uni-or multicentric dysplastic (intraepithelial neoplas­ tic) lesions, diagnostic and therapeutic methods more conservative than traditional conization are needed. The renaissance of colposcopy has fostered a more distinctive look at the spectrum of premalignant lesions and permitted a much more conservative approach to their management. Electrodiathermy, cryosurgery, and more recently carbon-dioxide laser have proven to be appropriate tools with which to destroy the atypical epithelia without mutilating the organs affected. The most important single factor involved in the success of these techniques is meticulous pretreatment assessment of the patient based on skilful colposcopic examination to determine the full extent of any lesion. This can only be done by a physician thoroughly experienced in col­ po scopic diagnosis and with a complete understanding of the histoge­ nesis of intraepithelial neoplasia.