Since the first case of gastric serrated adenoma found in 2001, 35 additional cases have been reported. Among these cases, 26 cases were associated with invasive adenocarcinoma within the serrated adenoma. Gastric serrated adenoma when compared with traditional adenoma has close correlation with invasive carcinoma. Serrated colorectal polyps are classified as hyperplastic polyps, sessile serrated adenoma/polyps, and tranditional serrated adenoma (TSA) depending on histological features. Two distinct phenotypes of TSA in the colon and rectum are reported. Those are unlocked serrated crypts (US-TSA) and ectopic crypt formations (ECFs). All gastric serrated adenoma are TSA in historical aspect and ECFs on phenotype. Whereas gastric adenomas are reported with high frequency in the antrum, gastric serrated adenomas are founded in the body and cardia. We report a case of a 60-year-old woman receiving endoscopic submucosal dissection for gastric serrated adenoma with adenocarcinoma discovered during routine screening.