A lymphatic cyst of the stomach is rare benign tumor which is composed of thin-walled lymphatic space lined by benign-appearing endothelial cells. It rarely manifests clinical symptoms, so it is found incidentally in most cases. Recently, a case of submucosal lymphatic cyst associated with early gastric cancer was experienced. An endoscopy revealed a slightly elevated, edematous lesion adjacent to the malignant ulcer. This case is herein reported with a brief review of related literature. (Korean J Gastrointest Endosc 2000;20:468-471)