The recommendations of proceeding in cases with CIN have significantly changed within the last years due to various reasons: Research on the biological development of CIN resulted in new concepts; as the age of patients showing-up with CIN decreased considerably, the need of more conservative diagnostic an therapeutic procedures became evident; it also was proved that human papilloma viruses contribute strongly to the etiology of CIN. So, objections against conization as the classical method of diagnosis and surgical treatment of CIN were increasingly substantiated. In order to find less invasive methods than conization, some alternatives were examined, and the combination of differential cytology, differential colposcopy and directed biopsy has proved in the meanwhile to be a valuable diagnostic alternative choice, not bearing the harmful implications of diagnostic conization. For therapy new methods have been elaborated as well, so electrocoagulation (= cauterization), cryosurgery and CO2-laser evaporization. All these methods allow a satisfactory treatment in most cases. We are recommending strongly to individualize and differentiate the procedures of diagnosis and treatment in CIN. Destructive surgery can be abandoned without taking the risk of inaccurate diagnosis or incomplete treatment.