Retroperitoneal hernias are rare. When they occur, they most often occur in naturally occurring fossas, such as with paraduodenal hernias. Due to the anatomy of the ureterovesicular system, patients with prior urological operations may be more likely to develop retroperitoneal hernias. We report the case of a 76-year-old male who had undergone a radical cystectomy with ileal loop conduit for bladder cancer, who presented with recurrent episodes of nausea and vomiting. Upon exploratory laparotomy, he was found to have a retroperitoneal hernia. The patient underwent resection of the strangulated loop of small bowel, and recovered without complications. In our patient, ureteral dissection from his prior procedure had created a defect in the peritoneum posterior to the sigmoid mesocolon, which allowed for herniation and subsequent strangulation of a portion of small bowel. Retroperitoneal hernias may represent an under-diagnosed etiology of intestinal obstruction in post-operative urological patients. Knowledge of anatomy is crucial in patients with previous abdominal operations, and prior operative notes should be reviewed, including non general surgical operations such as urological and gynecological procedures. The surgeon must remain vigilant in such cases of small bowel obstruction, as delayed intervention may lead to bowel compromise.