The Authors report the results of a controlled clinical study by means of colposcopy, cytology and target biopsy on 525 oral contraceptive (O.C.) users and 519 controls. Except for age class 31-35, more iodine dark cervices are found in cases, more iodine light (AnTZ and/or ectropion) in controls. The difference, although not statistically significant, suggests a protective role of O.C. on cervical epithelia. In 34 women (15 cases and 19 controls) CIN has been diagnosed. O.C. users show a more favorable situation, except for ages over 30 exposed to O.C. for less than 24 months. The Authors hypothesize a protective role of O.C. in younger women. While women aged 30 or more still appear protected when exposed to O.C. for more than two years (possibly from younger ages), these results suggest some caution in beginning oral contraception after the 30th year of age.