We report a 47-year-old man in whom Tc human serum albumin diethylene-triamine-pentaacetic acid protein-losing scintigraphy, performed with SPECT/CT, was useful for diagnosing Ménétrier disease. Planar images taken 1 and 3 hours after radioactive isotope injection yielded a suspicion that the stomach was the site of protein loss in this case. However, the protein loss from the stomach was precisely diagnosed after SPECT/CT was performed; this helped to diagnose Ménétrier disease.