We treated five patients with Hunter's glossitis following total gastrectomy. The major complaints of the patients were taste disorder and abnormal glossal sensation. In all five cases, the patient's tongue was red and smooth, and laboratory testing showed the presence of macrocytic anemia and decreased serum concentration of vitamin B12 (cyanocobalamin). Gustometry was carried out in four cases and the results documented the presence of taste disorder. All five patients were treated by administration of vitamin B12, which led to improvements in the appearance of the tongue, the patients' subjective complaints and the results of taste testing. When patients present with a red, smooth tongue, Hunter's glossitis (which can easily be improved by administration of vitamin B12) should be considered in the differential diagnosis.