A review of 59 consecutive cases of vaginal intraepithelial neoplasia seen in a colposcopy clinic between 1971 and 1984 was made. All patients presented with an abnormal Papanicolaou smear, and diagnosis was confirmed by colposcopically directed biopsy. The patients ranged in age from 23 to 72 years, with a mean age of 49. Fourteen (24%) patients were less than 40 years of age. A previous hysterectomy had been performed in 68% of patients, 42.5% of these being for benign disease. Forty-two patients (71%) had evidence of multicentric neoplasia of the lower genital tract, and 30 (51%) had been treated previously for cervical neoplasia. Twenty-nine lesions were multifocal and 52 (88%) were located in the upper third of the vagina. The results of the different modes of treatment were reviewed. Surgical extirpation gave the best results. The local ablative techniques used, ie, electrocautery and CO2 laser, were associated with failure rates of 25 and 50%, respectively. Three patients developed invasive carcinoma of the vagina after treatment.