BACKGROUND Villous adenoma is the one subtype of adenomatous polyp that is very uncommon in the stomach. Data regarding clinical characteristics, natural history, and prognosis were scarce. METHODS This report presented an 87-year-old Thai woman with a large gastric villous adenoma incidentally revealed in a computed tomography of chest for the evaluation of right pleural effusion. The esophagogastroduodenoscopy demonstrated a huge, glossy, proliferative polypoid mass involving gastric cardia, fundus, and a lesser curve of the upper body. The pathological report confirmed villous adenoma with low grade dysplasia. Although surgical resection was suggested, the patient denied any treatment due to advanced age and multiple comorbidities. She was generally well after 12 months of clinical and radiologic surveillance. CONCLUSIONS From literature review, only 14 cases of gastric villous adenoma were reported to date. Most of the lesions were large and symptomatic. Malignancy presented in 43% of the cases. Nevertheless, our patient remained asymptomatic without surgical removal following a 12-month period.