Abdominal aortic aneurysm is included in the differential diagnosis of lower back pain. Although rare, this important disease can cause potentially lethal complications. In this case, expanding abdominal aortic aneurysm coexisted with intervertebral disc extrusion. The diagnosis of abdominal aortic aneurysm was delayed, putting the patient at risk of aneurysmal rupture. In the management of patients with degenerative spinal diseases, we should not overlook the possibility of comorbidities such as an abdominal aortic aneurysm. We also suggest the importance of interpreting images more carefully, especially for elderly male patients.