A retroperitoneal organ injury-vascular injury or solid organ injury-that occurs during lumbar disc surgery needs to be dealt with adequately, because otherwise it could result in a poor (or, even, fatal) outcome of a “simple” procedure. Vascular injuries require special attention from the neurosurgical side (think of the possibility!) and cooperation between neurosurgeons and abdominal/vascular surgeons. In the presented case of a very obese female patient, a bite injury of the aorta during L3/4 disc surgery led to delayed intra-abdominal hemorrhage, which then required an emergency abdominal operation followed by major thromboembolic complication, and ultimately resulted in amputation of the patient’s healthy leg. Pitfalls in intraoperative diagnosis and postoperative care are discussed, along with related medicolegal issues.