A 68-year-old woman admitted to our hospital complaining of urinary incontinence and dysuria. On examination, the labia were found to be fused extensively, with a pinhole opening at the midline. Under spinal anesthesia, the adhesion was clearly separated with the Hegar's dilator. There remains no recurrence in this patient following therapy. The labial adhesion was considered to be an acquired disease caused by infection, trauma in the genitalia, or sexless life, according to hypoestrogenism.