Anatomical studies have demonstrated the high incidence of vasculitis in SLE, the appearances of which are variable and non-specific, ranging from necrotizing angiitis which is undistinguishable from periarteritis nodosa, to scarring lesions. Micro-angiitis is easily demonstrated in skin lesions and is also encountered to varying degrees in CNS, renal, cardiac, pulmonary and gastrointestinal localisations. Disease of large vessels is more rare and sometimes causes gangrene of the limbs. In SLE, vasculitis should be distinguished from thrombosis related to lupus anticoagulant and from atherosclerosis favoured by chronic steroid therapy but perhaps initiated by vascular deposits of immune complexes during the acute inflammatory stage. The treatment of lupic angiitis is mainly based on steroid therapy. The results are variable, probably due to the fibrous nature of some of the vascular lesions.