We herein report the case of a 58-year-old man with advanced esophageal carcinoma who developed posterior reversible encephalopathy syndrome (PRES). He initially presented with a severe consciousness disturbance. A subsequent examination revealed hypercalcemia and an elevated serum parathyroid hormone-related peptide (PTHrP) level. Magnetic resonance imaging performed on admission and 24 days later showed reversible widespread white matter abnormalities, which confirmed a diagnosis of PRES. The patient's clinical and radiological manifestations improved upon normalization of the serum calcium level. To the best of our knowledge, this is the first report describing hypercalcemia-induced PRES occurring in association with elevated PTHrP.