Gastric cancer has been the most commonly diagnosed cancer in Korea although the age-standardized mortality and incidence has decreased gradually during last two decades. $Helicobacter$ $pylori$ infection and cigarette smoking are well-established risk factors, and the role of dietary factors, such as salted foods, fresh vegetables and fruits, soy foods, and processed or grilled meats on gastric carcinogenesis has been suggested. In this review, we review national and international gastric cancer statistics, studies on environmental risk factors conducted in the Korean population, and gastric cancer screening activities.