|In Korea, about 30,000 gastric cancer (GC) cases are diagnosed yearly, and this was the most common type of cancer until 2010 when thyroid cancer took the top place. GC remains the leading cause of cancer incidence (17.8%) in men and the fourth most common cancer (9.4%) in women in 2014. The Korean government established the National Cancer Screening Program (NCSP) in 1999 for Medical Aid recipients and gradually expanded to include all the population aged 40 or more. NCSP provides gastric cancer screening every two years and participants can choose either upper-gastrointestinal series (UGIS) or endoscopy according to their preference. The participation rates increased from 7.4% among 9.6 million candidate people in 2002 to 45.4% among 13.0 million invited in 2011. Mortality reduction is the key parameter in evaluating the efficacy of screening program. In a nested case-control study performed using a cohort including more than 16 million- population showed that the overall odd ratio for dying from GC among ever-screened subjects was 0.79. According to screening modality, the ORs of death from GC were 0.53 for endoscopy and 0.98 for UGIS. A nationwide GC screening program using endoscopy in Korea proved effective in reducing GC mortality. Owing to the endoscopic screening, early gastric cancer proportion was dramatically increased. More than 25% of all GC can be treated by endoscopic resection in recent years. Endoscopic resection shows excellent outcomes compared with those of surgery if a lesion is within guidelines. However, expanded indication is not firmly established in Korea yet, especially for undifferentiated histologic types. Laparoscopic surgery has been widely accepted as a standard surgery for early GC and now the possibility to application to advanced GC in under prospective study. Several prospective surgical trials are ongoing especially for minimally invasive treatment for early GC. H. pylori infection is promising target for primary prevention of GC. However, since Korea started secondary prevention in about 15 years ago, primary prevention strategy is not currently incorporated into NCSP. We are currently performing randomized controlled trials on high risk group and general population to prove gastric cancer preventive effect of H. pylori eradication. With those results, we possibly change our secondary prevention strategy to encompass primary prevention strategy in near future.