{Reference Type}: Case Reports {Title}: Case report: Blood-transfusion induced posterior reversible encephalopathy syndrome. {Author}: Warr D;Sammon M;Zhou X;Mullen MT; {Journal}: Am J Emerg Med {Volume}: 83 {Issue}: 0 {Year}: 2024 Sep 20 {Factor}: 4.093 {DOI}: 10.1016/j.ajem.2024.07.026 {Abstract}: Posterior reversible encephalopathy syndrome (PRES) is an increasingly recognized clinical entity associated with a variety of medical conditions. It is commonly considered in the presentation of uncontrolled, severe hypertension. However, more recently, it has been described in the setting of blood transfusion, particularly in those with chronic anemia, even in the absence of severe hypertension. We describe a patient who presented to the emergency department 12 days after large blood transfusion for severe, chronic anemia with headache, vision loss, expressive aphasia and a change in mental status, with only mild blood pressure elevation, who was ultimately diagnosed with PRES and refractory non-convulsive status epilepticus. Emergency physicians are often the first to initiate blood transfusion for those with a low hemoglobin. Therefore, it is prudent to proceed with caution in transfusing those with chronic anemia. It is also important for the emergency physician to keep PRES on the differential for those presenting with a neurologic complaint after correction of their chronic anemia, even in the absence of severe hypertension.