Gastritis cystica polyposa (GCP) which is characterized by polypoid hyperplasia of the gastric mucosa, is known as an uncommon lesion that usually occurs at the gastroenterostomy site, although rarely it can be found in an unoperated stomach. Recently, GCP has been proposed to be a possible precancerous lesion itself. We present a rare case of GCP which presented as a large soft polypoid mass with a stalk in a previously unoperated stomach. A 44-year-old woman was admitted due to further study of large gastric mass. Previously, she had not undergone gastric surgery. Physical examination disclosed nothing abnormal. and laboratory test showed iron deficiency anemia. Endoscopy showed a large soft polypoid mass in gastric fundus and endoscopic ultrasonography showed a homogenous hypoechoic, and multilocular cystic mass with a stalk. We removed it via endoscopic polypectomy and histologic examination of this polypoid specimen showed the features consistent with the diagnosis of GCP. (Korean J Gastrointest Endosc 2001;22:212215)