The Authors have observed by colposcopy and cytology, 401 patients under the age of 20 and have compared the results obtained with those of a similar control group with ages ranging from 20 to 25. They observed the incidence of normal cervix and of other colposcopic reports. From the comparison between the colposcopic and cytologic data emerged that the cytopathologic diagnosis does not put the cervical alterations of inferior level than dysplasia in evidence, in a large number cases as colposcopy does. There is a very close relation between the incidence of pathologic cervical lesions and sexual activity. Correlation between cervical pathology and use of hormonal contraceptives and presence of cervico-vaginal phlogosis, was not possible in this type of survey. The Authors therefore propose a new type of mass screening, which should substitute the actual one, that is substantially based on cytology and on early diagnosis rather than prevention.