Introduction and objectives : Scleroderma is a connective tissue disorder ofunknown etiology, characterized by fibrosis and vascular obliteration in variousorgans. The pathogenesis of the diseases is not clearly understood, but vascularhyperactivity is a hallmark of the disease contributing to vascular occlusiontogether with thrombotic events. Annexin V inhibits prothrombin activation andis able to prevent thrombus formation, thus its auto antibodies are suspected toexert a determental role and interfere with its function. We studied serum antiannexin V level to evaluate its role and elucidate its frequency and clinicalsignifice in patients with scleroderma. Patients and methods: The studypopulation consisted of 40 patients with scleroderma. And control groupcomprising 15 healthy subjects of similar age and sex. Their serum wasexamined for IgG and IgM anti- annexin V antibodies by ELISA technique.Results: The mean serum level of antiannexinV Abs (IgG) were significantlyhigher in scleroderma patients versus the healthy control (P<0.001) while theIgM isotype show no difference (P=0.317). These antibodies (IgG and IgM)were not correlated to age or sex of patients nor the disease duration.Autoantibodies to annexin V IgG were found to relate to digital ulcers andamputation and also to some pulmonary manifestation including lung fibrosisand air flow limitation. Furthermore the IgM isotype was detected morefrequently in patients suffering from coronary heart lesions. Moreover, therewas correlation between IgG class and the presence of ANA. Conclusion: Wesuggest that anti- annexin V Abs may contribute to the disease process inscleroderma. In particular, may be related to the vascular involvement in thedisease. Thus closer follow up with these autoantibodies may enable earlydiagnosis of specific organ involvement and treatment of debilitating symptoms.