Posterior reversible encephalopathy syndrome (PRES) may present with different clinical symptoms including visual disturbance, headache, seizures and impaired consciousness. Brain MRI shows oedema, usually involving the posterior subcortical regions. Triggering factors include hypertension and obstructive sleep apnea syndrome. The mechanism underlying PRES is under debate, but endothelial dysfunction is implicated. Treatment goals of PRES are gradual blood pressure (BP) lowering to avoid sudden hypoperfusion of vital organs and prevention and management of seizures. PRES usually has a favorable prognosis, but delayed diagnosis and treatment may lead to cardiovascular morbidity, mortality or irreversible neurological deficits.