A rare case of aneurysm of the lateral sacral artery is reported. This 46-year-old female presented with complaints of bowel and bladder incontinence and decreased perianal sensation for the past 15 months. She underwent laminectomy and diskectomy for the diagnosis of a prolapsed disk at peripheral hospital where the surgeon was confronted with a severe and unexpected hemorrhage, and surgery was aborted without effective treatment. Prior medical history includes hypertensive kidney disease with a renal transplant eight years ago. Magnetic resonance imaging and angiographic findings were suggestive of a lateral sacral artery aneurysm. Patient with a history of renal transplant and presenting with cauda equina require a more thorough assessment, and a differential of lateral sacral artery aneurysm should always be kept in mind. Our purpose is to report the pre-operative features of the lateral sacral artery aneurysm and its treatment modalities.