This study comprised the largest number (76) of cases of vaginal intraepithelial neoplasia (VaIN) so far reported. Women diagnosed with VaIN were older (mean age 50.2 years) than those diagnosed with cervical intraepithelial neoplasia (CIN). Many of the women had previously undergone (71.2%). In the majority of cases, the diagnosis was made after cytologic testing. In 92.4% of the cases, the lesions affected the upper third of the vagina. Grades of VaIN were distributed as follows: grade 1 52.6%, grade 2 191.%, grade 3 28.9%, with a 15-year interval between VaIN 1 and 2 as a group and VaIN 3 as another group. The cases of VaIN were divided into five groups: VaIN de novo; VaIN + CIN; VaIN postradiotherapy; VaIN + CIN + VIN; and incidental finding of VaIN on the surgical specimen. The therapeutic modalities were heterogeneous; CO2 laser therapy was used most frequently (54.2%). Failures are attributed mainly to the multifocal character of the lesions (particularly with human papilloma virus infection) or their localization in the vaginal angles. Overall, the number of cases, the duration of follow-up (39.2 months), and the unsatisfactory results with CO2 laser therapy have led us to propose a therapeutic decision tree where in which 5-fluorouracil plays a major role, CO2 laser and surgical therapeutic modalities having limited and precise indications.