Study Objective To demonstrate a technique for hysteroscopic diagnosis and management of a rare variant of Herlyn-Werner-Wunderlich syndrome (HWWS) in a virgin girl. Design Presentation of a rare variant of HWWS and a step-by-step description of the technique using videos, images, and title slides (educative video) (Canadian Task Force classification III). Setting HWWS is a congenital anomaly of the urogenital tract, typically characterized by uterus didelphys, obstructed hemivagina, and ipsilateral renal agenesis. Of HWWS cases, 11.5% are a rare variant of the syndrome, with a septate bicollis uterus and obstructed hemivagina. HWWS is often diagnosed in adolescent girls and virgin patients. Early diagnosis and treatment should be achieved using a convenient, minimally invasive, and effective surgical approach to prevent complications. Interventions A 14-year-old virgin girl had aggressive cyclic dysmenorrhea for 7 months. We made a diagnosis of the non-classic HWWS variant: septate uterus with double cervix, obstructed right hemivagina with hematocolpos, and unilateral renal agenesis. Diagnostic hysteroscopy indicated a flat hemivaginal septum, left cervix, and uterine cavity, but no right cervix or other associated channel. Hysteroscopic incision of the bulging oblique vaginal septum was performed medially from the most prominent point of the septum up to the left cervix and then down to the low edge of the oblique septum. An inflated Foley catheter was placed in the right hemivagina for 2 days to prevent adhesion of the incised septum. Surgery was successful, and the intact hymen was preserved. The patient has been symptom-free for 4 months after surgery. Conclusion Hysteroscopic incision of the oblique vaginal septum is a convenient, minimally invasive, and effective approach for treating HWWS in adolescents with cyclic dysmenorrhea and hematocolpos.