Thromboangiitis obliterans (TAO, Buerger's disease) is an idiopathic, recurrent, segmental, nonatherosclerotic, inflammatory, occlusive vascular disease with a poorly understood pathogenesis. Intestinal or multi-organ involvement is rare. Recent immunohistochemical analyses of ordinary TAO have indicated an inflammatory and immunologic pathogenesis. We report a case of TAO involving multiple large vessels. By immunohistochemistry, CD3+ T cells were revealed around the recanalization sites within the abdominal aorta. CD4+ T cells were almost equal in number to CD8+ T cells. These findings indicate the participation of inflammatory and immunologic processes in TAO with multi-organ involvement (as in ordinary TAO).