BACKGROUND: Obstructed hemivagina and ipsilateral renal anomaly (OHVIRA), or Herlyn-Werner-Wunderlich syndrome, is a rare Mullerian duct anomaly with uterus didelphys, unilateral obstructed hemivagina, and ipsilateral renal agenesis. Patients with this anomaly usually present after menarche with pelvic pain and/or a mass and rarely, in later years, with primary infertility. Strong suspicion and knowledge of this anomaly are essential for a precise diagnosis. Although the true incidence is unknown, it has been reported to be between 0.1% and 3.8%, with only a few reported cases of the syndrome occurring during pregnancy. CASE: A 21-year-old, nulligravid woman at 14 weeks of gestation was referred due to lower abdominal and pelvic pain, genital bleeding and purulent genital discharge. History of congenital intestinal malformation operated. Examination revealed an ill-defined tender mass at the right iliac fossa. A transvaginal ultrasound was performed, which suggested a uterine didelphys, 14+3 weeks gestation and hematometra. To better elucidate the complex findings from the ultrasound, an MRI was obtained: uterus didelphys associated with vaginal double with longitudinal nonobstructive septum. The right hemivagina was markedly distended, ipsilateral agenesis of right kidney. Surgical management was decided with resection of vaginal septum, and subsequent treatment to reduce the risk of vaginal synechia. Currently the patient is in a 30-weeks pregnant, in overall good conditions. Conclusion: Given the high rate of associated complications in this syndrome, it is justified to handle a high index of suspicion. The importance of early detection and adequate surgical management will avoid its complications. Before a patient becomes pregnant in which a OVHIRA syndrome, surgical resection of the obstructive vaginal septum allows rapid relief of symptoms and prevention of possible complications related to pregnancy.