Posterior reversible encephalopathy syndrome is a rare and serious neurologic adverse effect of calcineurin inhibitors. The pathophysiology of this clinical entity is still unclear. Impaired cerebral autoregulation and endothelial dysfunction are thought to be the main pathologic processes. Imaging shows the syndrome to be characterized by vasogenic edema or cytotoxic edema in parietal and occipital areas of the brain. With regard to clinic presentation, headache, diminished visual acuity, cortical blindness, altered consciousness, seizures, and hallucinations can be seen. It is known that the clinical presentation is improved when calcineurin inhibitors are stopped early. Here, we present and evaluate a case of a cortical blindness that developed in a 36-year-old patient who had been using tacrolimus after renal transplant and who returned to health after 1 week of hospitalization.