Background: Transverse vaginal septa are rare anomalies that may be diagnosed for the first time during labor. Case: A 29-year-old nulliparous woman without a prior appointment, who had been married for 11 years, presented with labor pains at 39 weeks of gestation. On examination, she was diagnosed as having a transverse vaginal septum with a pinpoint septal opening. Emergency cesarean section, followed by dilatation of the septum, was performed. Results: The postoperative period was uneventful. Conclusions: To avoid obstructed labor and injuries to the patient, prophylactic cesarean section is recommended in patients presenting with transverse vaginal septum in labor, especially in women who have conceived after a long period of infertility. ( J GYNECOL SURG 29:207)