OBJECTIVES: 　Although gastric cancer has decreased in the last three decades, it is still the second leading cause of cancer death worldwide. In Asian countries, the burden of gastric cancer has remained, and screening is still expected to prevent gastric cancer death. In order to evaluate reduction of mortality from gastric cancer by endoscopic screening, a community-based, case-control study was conducted in Japan. METHODS: Case subjects were defined as persons who had died of gastric cancer between 2003 and 2006 in four cities, Tottori Prefecture, and between 2006 and 2010 in Niigata City, Japan. Up to six control subjects were matched by sex, birth year (±3 years), and residence of each corresponding case from population lists in the study areas. Controls were required to be disease-free at the time when the case was diagnosed gastric cancer. The odds ratios were calculated for those who had ever participated in endoscopic screening or radiographic screening before the reference date when the case was diagnosed gastric cancer, compared with persons who had never participated in any screening. Conditional logistic-regression models for matched sets were used to estimate the odds ratios and 95% confidence intervals.  RESULTS: There were 288 males and 122 females for case subjects, with 2,292 matched control subjects. Compared with those who had never been screened before the date of diagnosis of gastric cancer in cases, the odds ratios within 48 months from the diagnosis  date were 0.703 (95% confidence interval :0.497-0.996) for endoscopic screening and 0.860 (95% confidence interval :0.631-1.171) for radiographic screening.  CONCLUSIONS: The result suggests a 30% reduction from gastric cancer mortality by endoscopic screening compared to no screening within 48 months before the diagnosis date of gastric cancer.