Posterior reversible encephalopathy syndrome is characterized by visual and mental disturbances, nausea and vomiting and generalized or focal convulsions and often represents itself with parietal and occipital oedema formation. We want to report the treatment of posterior reversible encephalopathy syndrome with plasmapheresis, which developed in a 35-year-old woman with systemic lupus erythematosus diagnosed by renal biopsy 3 years ago. She has been followed up in the intensive care unit three times. However, she had been transferred to the nephrology department of our university hospital because of her uncontrolled blood pressure. Oral antihypertensive therapy, corticosteroid 500 mg 1 x 1 and cyclophosphamide were started for the activation of lupus. After the detection of low complement levels, systemic lupus erythematosus activation was suspected. She developed mental deterioration after her first plasmapheresis treatment and was then consulted by the neurology and intensive care unit doctors. Diffusion cranial magnetic resonance imaging was found compatible with posterior reversible encephalopathy syndrome. The patient was transferred to our intensive care unit. The patient gained consciousness after her second plasmapheresis. After 5 days of follow-up in our intensive care unit and after significant regression was observed in the magnetic resonance imaging analysis, the patient was transferred to the nephrology service conscious, cooperated and orientated. At the nephrology service, after a total of 13 times of plasmapheresis, complement levels were increased and she was discharged with corticosteroid therapy. Posterior reversible encephalopathy syndrome can be observed in patients with systemic lupus erythematosus and intensive care unit treatment may be required. To control the hypertension, plasmapheresis should be kept in mind in addition to the multiple antihypertensive therapy in these patients.