Vulvar intraepithelial neoplasia and VAIN present unique challenges to the practicing gynecologist. VIN may produce distressing symptoms and undergo malignant conversion. A high index of suspicion and liberal use of biopsy are required to make the diagnosis. The approach to therapy for VIN has been reviewed. Treatment should be tailored to each individual patient and may include a period of expectant observation. Variations and combinations are used whenever necessary to preserve normal function and anatomy. Frequent surveillance is a must because recurrence rates are high, especially with multifocal disease in young women. Although VAIN accounts for less than 0.5% of lower genital tract neoplasia, the frequency of its detection is increasing, especially in younger patients. These lesions are most commonly found in the upper third of the vagina and are often multifocal in nature. The close proximity of the upper vagina to the rectum, bladder, and ureters makes treatment difficult. The occult invasion rate may be as high as 28%, and a wide variety of therapies are available. As is true for VIN, recurrence is not uncommon.