Labial fusion is a clinical entity rarely seen in adults. The reported case is a 25 years old, single, sexually inactive young adult with a regular menstrual pattern who presented to our clinic with closure of the vaginal introitus. Previous history regarding chronic conditions was not significant. Topical estrogen cream had been applied for one year with no benefit. Labo-ratory work-up revealed overt hypothyroidism. Levels of gonadotropins, estrogen, and an-drogens were normal. Complete fusion of the labia minora ending at the posterior fourchette was observed in genital examination. The clitoris could not be visualized and only a central 0.5 cm diameter surrounded by synechiae was seen. Surgical lysis was performed under sedative anesthesia to separate the labia. Labial fusion is usually seen in early childhood or postmenopausal years, but may arise idiopathically in adults without etiologic factors such as hypoestrogenism, chronic irritation, and infections of the vulva.