<b>Introduction:</b> Herlyn-Werner-Wunderlich (HWW)/obstructed hemivagina and ipsilateral renal agenesis (OHVIRA) syndrome is a rare Müllerian duct anomaly (MDA). Usually presenting after menarche classically with dysmenorrhea. Here we present a challenging case, where the diagnosis was missed initially.<br />
<b>Case presentation:</b> A 10-year-old girl presenting with dysmenorrhea and constipation, treated repeatedly with analgesics, laxatives and enema. A pelvic ultrasound and magnetic resonance imaging (MRI) confirmed the diagnosis of OHVIRA syndrome, which requires surgical intervention. We describe a “no -touch- technique” for resecting the septum. The patient had immediate relief of symptoms and a smooth post-operative recovery.<br />
<b>Conclusions:</b> Early diagnosis and surgical management are crucial not only to relieve symptoms but to prevent long term complications that may affect the patients’ reproductive potential. Despite pelvic ultrasound being an affordable and a useful diagnostic tool, the diagnosis can be missed by inexperienced operators. Therefore, MRI is recommended to confirm and classify MDAs. The hysteroscopic “no-touch-technique” to resect the septum is an effective, safe and a convenient approach to treat the condition while preserving hymen integrity.