OBJECTIVES: This study was performed to evaluate the effect of stage shift according to screening of stomach cancer. METHODS: Total 840 cases of stomach cancer patients, undergone a surgical operation at Department of Surgery, Kangnam St. Mary's Hospital, The Catholic University of Korea from Jan. 1989 to Dec. 1995, were reviewed by stomach cancer working sheet, and classified as asymptomatic and symptomatic group based on the presence of subjective symptoms on their hospital visit. Their histopathologic stages were analysed. We compared the histopathologic stages of asymptomatic stomach cancer patients with those of symptomatic patients. RESULTS: From the total of 840 patients, asymptomatic patients group comprised 28 cases (3.3%). Proportion of asymptomatic patients tended to increase from 1.9% in 1990, 0.9% in 1991 to 8.6% in 1995. Proportions of asymptomatic patients by stages were 78.6% (stage I), 3.6% (stage III), 17.9% (stage IV) and that of symptomatic patients by stages were 38.2% (stage I), 16.5% (stage II), 24.8% (stage III), 19.1% (stage IV). In less than 40 years old, 50.5% of symptomatic patients were diagnosed as stage I. With increment of ages, proportions of stage I were markedly decreased. It was significantly different between proportion of early gastric cancer in asymptomatic patients (60.1%) and that in symptomatic patients (25.0%). CONCLUSIONS: We confirmed stage shift according to screening of stomach cancer. And proportion of early gastric cancer in asymptomatic patients was higher than that in symptomatic patients. This results suggest that screening of gastric cancer be important to reduce mortality and it be indirectly started from 40 years old.