Posterior reversible encephalopathy syndrome (PRES) is an unusual condition typified by acute visual impairment caused by sudden, marked parieto-occipital vasogenic edema. Thought to be inflammatory in origin, it has been described in patients undergoing chemotherapy, with autoimmune disease, and in some infections. We report a case of PRES that occurred one week after an episode of acute pancreatitis in an otherwise healthy 40-year-old female. There was progressive visual impairment over a 24-hour period with almost complete visual loss, with characteristic findings on magnetic resonance imaging. After treatment with steroids, the visual loss recovered. Clinicians should retain an index of suspicion of this rare condition in patients with visual impairment after acute pancreatitis.