We report 62-year-old female patient with coincident posterior reversible encephalopathy syndrome (PRES) and Guillain-Barré syndrome (GBS). The first presentation of PRES was a generalised tonic-clonic seizure. A risk factor for PRES was acute arterial hypertension. The diagnosis of PRES was established by MRI (magnetic resonance imaging) and hypertension was treated with labetalol 800mg daily followed by regression of symptoms of PRES. Two days after the seizure the first motor signs of GBS presented with a weakness in both upper arms. The diagnosis of GBS was finally established 6 days after the seizure by clinical evolution, lumbar puncture and electrophysiological findings. After treatment of GBS with intravenous immunoglobulins (IVIg), antihypertensive therapy could be phased out and finally stopped. The patient was discharged after 25 days without any medication. At that time she was completely recovered from PRES and recovering well from GBS. The acute arterial hypertension, the provoking factor of PRES, was probably caused by an autonomic dysfunction in the context of GBS before motor signs of GBS were present but we speculate also that there are other GBS related factors playing a role in PRES. This hypothesis is based on the relatively high coincidence of these two rare syndromes which appears from a review of the literature. One other possible mechanism can be the influence of cytokines, produced in the context of a GBS, on the permeability of blood brain barrier.