Posterior reversible encephalopathy syndrome (PRES) is characterised by sudden hypertension that is associated with headache, seizure, visual disturbance and altered mental function. We report a 62-year-old woman with a sudden onset of complete bilateral visual loss, an admission blood pressure (BP) of 204/113mmHg, and flaccid weakness in all four limbs. The patient's cerebrospinal fluid and nerve conduction studies were consistent with a diagnosis of Guillain-Barré syndrome (GBS) and her brain MRI showed classic features of PRES. Her blood pressure was managed appropriately and her GBS was treated with plasmapheresis. Two months following presentation, the patient's vision recovered completely and she regained full power of her four limbs. She did not need any continuing antihypertensive medication. This report is the 8th of accumulating evidence that links PRES with GBS, and it shows that PRES can be the presenting feature following GBS treatment with intravenous (IV) immunoglobulins or later in recovery. Dysautonomia resulting from GBS is the most likely explanation of this strong association. GBS is mostly reversible when managed correctly; however, the literature suggests that failure to recognize or delay treatment can lead to cerebral infarction or even death.