Pelvic organ prolapse is rarely associated with severe bilateral ureteral hydronephrosis and renal dysfunction. The etiopathogenetic mechanism has not been fully elucidated. Contemporary imaging methods of the urinary tract play a decisive role in assessing the morphological function of the kidneys. In cases of moderate and severe pelvic organ prolapse, surgery appears to be the main choice of treatment. Our case concerns a post-menopausal patient with three vaginal deliveries in her obstetric history and with a history of bilateral hydronephrosis and impaired renal function who was referred to the outpatient clinic for a gynecological examination due to complete uterine prolapse. Bilateral hydroureteronephrosis due to prolapse was assessed as the main cause of renal dysfunction. A surgical intervention was decided to the pelvic floor and a vaginal hysterectomy was performed with simultaneous correction of the cystocele and rectocele. The postoperative course was uneventful. Three months later, re-examination of the urinary tract showed complete remediation of kidney morphology and function. The present case report emphasizes the significant degree of bilateral hydroureteronephrosis and deterioration of renal function rarely seen in patients with complete uterine prolapse. At the same time, it is pointed out that the exclusion of renal dysfunction related to complete uterine prolapse should be the main concern of the modern gynecologist even for complex cases with coexisting etiological factors for renal disease, in order to avoid permanent renal parenchymal damage and ensure the best health and quality of life of these patients.