Objective To investigate the clinical and MRI features and pathogenic mechanism of posterior reversible encephalopathy syndrome (PRES) in patients with systemic lupus erythematosus (SLE).Methods Six cases of PRES in SLE proved by integrated clinical diagnosis were collected from January 2008 to December 2013.The clinical and MRI features of these patients were studied retrospectively and the related literatures were reviewed.Results The initial episode of nervous system was involved in 4 cases.The clinical presentations were headache (2 cases),seizures (4 cases),acute confusion state (2 cases),altered mentation (1 case) and vision change (1 case).All cases had lupus nephritis and hypertension,in which 4 cases had renal failure;6 cases were treated with immunosuppressive agents and 4 cases with cyclophosphamide for lupus nephritis when they developed PRES.The vasogenic edema lesions were distributed in the parietal or occipital lobe (5 cases),the frontal lobe (4 cases),temporal lobe (4 cases),basal ganglia (3 cases),splenium (1 case) and cerebellar hemispheres (2 cases).Three major patterns of PRES included dominant parietal-occipital (2 cases),the holohemispheric watershed (3 cases),and superior frontal sulcal (1 case).Conclusions The clinical and MRI findings of PRES in patients with SLE are typical.Awareness of this entity as early as possible can help to improve curative effect and prognosis.