Posterior reversible leukoencephalopathy syndrome (PRES) is characterized by transient headache, altered mental functioning, seizures, and loss of vision associated with findings of predominantly posterior cerebral lesions on imaging studies. Magnetic resonance imaging typically shows bilateral hyperintensity on T2 weighted imaging and fluid attenuated inversion recovery imaging, predominantly in the parieto-occipital region. The common etiologies of PRES include eclampsia, renal impairment, immunosuppressive treatment, cancer chemotherapy, autoimmune diseases, and hypertension. The prognosis is usually benign when adequate treatment is initiated immediately. Otherwise, delay in diagnosis and treatment may lead to permanent neurological sequelae. We report on the case of a 24-year-old man who presented with the characteristics of PRES with acute carbon monoxide poisoning.