Background: Herlyn-Werner-Wunderlich syndrome is a rare Müllerian-duct anomaly consisting of uterine didelphys, a unilateral obstructed hemivagina, and ipsilateral renal agenesis. This article presents clinical and laparoscopic findings as well as the surgical management of 5 cases with various clinical scenarios. Cases: Case 1: An 11-year-old premenarchal female presented with chronic vaginal discharge and negative cultures. She had a uterus didelphys, a unilateral partial obstructed hemivagina, and ipsilateral renal agenesis. She underwent excision of the hemivagina. Case 2: A 14-year-old female presented with severe dysmenorrhea. As part of the work-up for a two-vessel cord at birth, an ultrasound revealed an absent left kidney. Magnetic resonance imaging suggested uterine didelphys and a left hematometrocolpos. At surgery, the MRI findings were confirmed. She underwent excision of the left hemivagina. Case 3: A 23-year-old asymptomatic female was referred following an incidental finding of a duplicated uterine horn and hematocolpos on ultrasound. She had a uterus didelphys, a unilateral obstructed hemivagina, and ipsilateral renal agenesis. She underwent excision of the hemivagina. Case 4: A 26-year-old female presented with severe dysmenorrhea and chronic pelvic pain. She had a uterus didelphys and a high right-sided obstructed hemivagina, with no hematocolpos, hematometra, hematosalpinx, endometrioma, and ipsilateral renal agenesis. She underwent a hemihysterectomy, unilateral salpingectomy, and endometrioma excision. Case 5: A 15-year-old female had a history of severe dysmenorrhea. During laparoscopy for an acute abdomen, she was noted to have uterus didelphys. Further evaluation revealed a hypoplastic cervix and a high right-sided obstructed hemivagina, with minimal hematocolpos, hematometra and ipsilateral renal agenesis. She underwent a hemihysterectomy. Results: The patients recovered well and, in most cases, had complete resolution of their symptoms. In Case 4, the patient's symptoms were greatly reduced. Conclusions: In patients with obstructed hemivaginas that are diagnosed early, resection of the vaginal septum is a convenient and effective treatment modality. Hemihysterectomy should be considered in patients with cervical hypoplasia/ aplasia and high position of obstructed hemivaginas, and in patients with severe endometriosis, tubal damage, and extensive pelvic adhesions. ( J GYNECOL SURG 31:46)