Thromboangiitis obliterans (TAO) is a non-atherosclerotic inflammatory arthritis mainly involving small arteries and veins. Although it is closely related to the tobacco exposure, the general pathophysiology of the disease remains unclear. TAO mainly affects young male patients with ischemic ulcer, pain during rest, limping, chills in limbs, and migratory thrombophlebitis. However, some patients present joints swelling and pain as the first manifestations before the clinical manifestations above. They are easy to be misdiagnosed as rheumatic diseases, which is a challenge to the diagnosis and treatment of rheumatologists. Here we report a case in which TAO was misdiagnosed as Seronegative Spondyloarthritis (SpA) and eventually amputated.