Devastating complications of the bladder outlet resulting from prostate cancer treatments are relatively uncommon. However, the combination of the high incidence of prostate cancer and patient longevity after treatment have raised awareness of adverse outcomes deteriorating patients' quality of life. This narrative review discusses the diagnostic work-up and management options for bladder outlet obstruction resulting from prostate cancer treatments, including those that require urinary diversion. The devastated bladder outlet can be a consequence of the treatment of benign conditions, but more frequently from complications of pelvic cancer treatments. Regardless of etiology, the initial treatment ladder involves endoluminal options such as dilation and direct vision internal urethrotomy, with or without intralesional injection of anti-fibrotic agents. If these conservative strategies fail, surgical reconstruction should be considered. Although surgical reconstruction provides the best prospect of durable success, reconstructive procedures are also associated with serious complications. In the worst circumstances, such as prior radiotherapy, failed reconstruction, devastated bladder outlet with end-stage bladders, or patient's severe comorbidities, reconstruction may neither be realistic nor justified. Urinary diversion with or without cystectomy may be the best option for these patients. Thorough patient counseling before treatment selection is of utmost importance. Outcomes and repercussions on quality of life vary extensively with management options. Meticulous preoperative diagnostic evaluation is paramount in selecting the right treatment strategy for each individual patient. The risk of bladder outlet obstruction, and its severest form, devastated bladder outlet, after treatment of prostate cancer is not negligible, especially following radiation. Management includes endoluminal treatment, open or robot-assisted laparoscopic reconstruction, and urinary diversion in the worst circumstances, with varying success rates.