Posterior reversible encephalopathy syndrome (PRES)or Reversible posterior leukoencephalopathy syndrome (RPLS) is a neurological complication associated with various illnesses and medications(including rheumatological illnesses and their medications). Cyclosporine is the drug which is most commonly implicated in the causation of this condition. The authors report a 6 year old patient with systemic onset juvenile idiopathic arthritis (SoJIA) with macrophage activation syndrome who developed PRES during treatment with pulse methylprednsiolone therapy. In view of persitent SoJIA disease activity, the child was subsequently treated with Cyclosporine. The child made a complete neurological recovery. This case report highlights that, in accordance with recent literature, PRES is a complication of a unique set of conditions comprising of inflammation, hypertension, immunosupression and nephropathy in different degrees and does not necessarily preclude the use of drugs implicated as inciting agents. This has important implications in rheumatology where cyclosporine is a life saving medication used in macrophage activation syndrome.