Background: Herlyn-Werner-Wunderlich syndrome(HWWs) is a rare congenital urogenital anomaly characterized by the triad of uterus didelphys, obstructed hemivagina, and ipsilateral renal agenesis. HWWs is usually diagnosed after menarche with symptoms of pelvic pain, dysmenorrhea, and a palpable mass due to hematocolpos or hematometra, and often associated with long-term complications such as endometriosis, pelvic adhesions, and increased risk of recurrent pregnancy loss or infertility. Case description: A 26-year-old woman was referred to the hospital with complaints of 8-month history of dysmenorrhea and had been diagnosed with a bicornuate uterus. Bimanual examination showed hematocolpos on the left side of the cervix and an 8 cm painless mass on both of adnexa. Speculum examination showed vaginal septae at the 7 o’clock direction, on the left side of the cervix with dark blood coming from the right side of the cervix. Her transvaginal ultrasound examination showed the presence of a bicornuate uterus.Agenesis of the right kidney and didelphys uterus with right-sided hematocolpos resulting from obstructed hemivagina were detected by magnetic resonance imaging (MRI).Based on clinical and radiographic examinations, the patient was diagnosed with HWWs with a huge endometrioma and treated with laparoscopic cystectomy, hysteroscopy dan excision of vaginal septae.Conclusion: An accurate diagnosis is needed in the management of the HWWs case so that it can be treated early and can improve the patient's quality of life. Because this case is rare, health facilities need to gain an understanding of the proper diagnostic procedure.