Lichen planus and GVH disease are both inflammatory processes, which can present with a range of clinical conditions. Each may result in the development of irritative symptoms and erosive lesions on mucosal surfaces. Although lichen planus is a well-defined dermatosis, GVH disease is an iatrogenic process. We report the case history of a patient with erosive vulvovaginal lesions with scarring, likely caused by GVH disease, which mimicked erosive vulvovaginal lichen planus. Although the clinical presentation and treatment of these 2 entities are similar, this case demonstrates the subtle diagnostic difference between the 2 diseases.