Pseudo aneurysms of the axillary artery are rare but are potentially dangerous lesions that threaten the upper extremity with vascular and neurologic compromise. A case of pseudoaneurysm of the axillary artery after a pocketknife stab wound to the left shoulder is presented. The lesion was confirmed with selective angiography of the axillary artery. Successful surgical treatment by aneurysmectomy with subclavian-axillary bypass was achieved. A brief history of these aneurysms and their pathogenesis, presentation, diagnosis, and treatment are reviewed.