Renal involvement in systemic lupus erythematosus is a frequent and serious complication that significantly increases morbidity and mortality. Despite all studies and usage of new drugs, treatment of lupus nephritis continues to be a problem. Diffuse proliferative lupus nephritis has a poor prognosis and aggressive treatment must be undertaken. Cyclophosphamide is commonly used in treatment despite its side effects. Reversible posterior leucoencephalopathy syndrome is a clinico-radiological syndrome manifested by blood pressure elevation, headache, visual disturbances, confusion, seizures and sometimes focal neurological signs that can develop due to usage of cytotoxic drugs. We present a case of lupus nephritis in which reversible posterior leucoencephalopathy syndrome developed after intravenous cyclophosphamide administration and recovered spontaneously by symptomatic treatment in this article.