An 82-year-old Japanese man underwent esophagogastroduodenoscopy for postprandial epigastric discomfort. The patient was diagnosed with hypozincemia with a serum zinc level of 63μg/dL (normal range:80-130μg/dL), and he had commenced oral intake of zinc acetate 1 month before the esophagogastroduodenoscopy. Endoscopy showed erosions with white-coated mucosa surface adhesions and erythema on the lesser curvature of the gastric body. Moderately differentiated tubular adenocarcinoma was suspected based on the biopsy examination findings;therefore, he was referred to our hospital for further examination and treatment. A repeat endoscopy showed two erosions with white-coated mucosa surface adhesion and erythema on the lesser curvature of the gastric body. However, the lesion location was different from that detected in the initial endoscopy. The biopsy showed no neoplastic changes. Therefore, based on the endoscopic findings and history of oral zinc acetate administration, we diagnosed the gastric mucosal injury as zinc acetate-associated gastric lesions. The cessation of zinc acetate intake resulted in the resolution of gastric lesions. Reassessment of the biopsy specimen from the initial endoscopy revealed erosions, epithelial cells showing infarct-like necrosis, degenerative atypical cells, and necrotic substances, which were misdiagnosed as neoplastic changes. This case highlights the importance of recognizing the typical endoscopic features of a zinc acetate-associated gastric lesion to enable its prompt diagnosis during esophagogastroduodenoscopy.