A married woman of reproductive age had labial adhesion with voiding difficulty. She and her husband had not been bothered by their inability to engage in sexual intercourse for the 10 years of their marriage. Surgical incision and reconstruction disclosed the normal vaginal vestibule and urethral meatus. Six months after surgery, her labium was fully open without recurrence. We must be aware that labial adhesion may occur and be hidden in a woman of reproductive age, even when the patient does not notice any ‘abnormality’ in her genitalia.