Objective: To identify risk factors for the appearance of vaginal intraepithelial neoplasia (VAIN). Material and methods: A total of 485 women with abnormal cytologies were followed over three years (2003-2006). They underwent cytolology and colposcopy, and testing for human papillomavirus virus (HPV) infection. If the colposcopy was atypical, a biopsy was performed. Results: A total of 256 women were treated: 161 by cone biopsy, 103 by LLETZ, 12 by repeat conization, and 44 by total hysterectomy. In eight cases VAIN was diagnosed following hysterectomy. The average age at which VAIN appeared was 49.8 years (age range 39-61). Hysterectomy was indicated in two cases of cervical cancer, four cases of persistent high-grade cervical SIL, and two cases of recurrent high-grade cervical SIL. The mean time for the appearance of VAIN following hysterectomy was 3.8 years (range 1-9 years). Of these eight women, seven had HPV infections at high risk for carcinogenesis. Conclusions: Long-term follow-up cytology is necessary for women treated for high-grade SIL, even after hysterectomy, because of the increased risk of a primary vaginal VAIN lesion, especially in women with high-risk HPV infection.