Bedside ultrasound is the diagnostic method of choice for unstable patients with suspected abdominal aortic aneurysm. Its ability to provide rapid and accurate diagnosis is critical in an emergency setting. Previous studies have documented the ability of Emergency Physicians to accurately diagnose abdominal aortic aneurysms, thus potentially saving lives. A search of the medical literature did not reveal any reports of false positive abdominal aortic aneurysm diagnosis with ultrasound use. We report a case of a false positive abdominal aortic aneurysm diagnosed in a patient with a previously unknown large malignant para-aortic lymph node.