Posterior reversible encephalopathy syndrome (PRES) is a clinico- radiological syndrome characterized clinically by headache, seizures, visual disturbances, vomiting and radiologically by predominant posterior leukoencephalopathy. The authors report an 11-y-old boy with meningitis presenting with transient hypertension and visual loss and MRI finding compatible with the diagnosis of PRES and complete reversal of symptomatology within 10 d. A wide plethora of tests carried out failed to identify the cause of transient hypertension with a probability of this being due to transient autonomic dysfunction.