We present the case of a 33-year-old male with end stage renal disease presenting to theemergency department (ED) with headache, dizziness, and unilateral weakness. Initial concern wasfor ischemic or hemorrhagic stroke. Magnetic resonance imaging confirmed posterior reversibleencephalopathy syndrome (PRES). The patient was treated appropriately and made a fullneurologic recovery. PRES is an under-recognized diagnosis in the ED. As a stroke mimic, PREScan lead the clinician on an incorrect diagnostic pathway with potential for iatrogenic harm.