Autoantibodies, organ and non-organ specific, were studied in 10 patients of thromboangiitis obliterans by immunofluorescence technique and compared with age matched controls without peripheral vascular disease and patients of other peripheral vascular diseases. Organ specific autoantibodies (various classes of immunoglobulins IgM, IgG, IgA) and C3 component were observed in the diseased vessels of thromboangiitis obliterans. Antibodies, antiarterial, were present in the sera of these patients. Among the non-organ specific antibodies (ANA and AMA), only ANA were found in the sera of patients. Presence of autoantibodies in patients of thromboangiitis obliterans strongly point out of that probably this disease entity is an autoimmune disorder.