PURPOSE: There are several kinds of classificatian dealing with the staging of the gastric adenocarcinoma. However, such different staging systems pose difficulty in the inter- institutional or intemational comparison of the disease status and the treatment results. The purpose of this study is to evaluate each staging system and to assess the usefulness of the new UICC-TNM staging system (1997) for gastric adenocarcinoma. MATERIAL AND METHODS: We retrospectively analysed 473 cases of gastric adenocarcinoma who were operated at the Department of General Surgery, Hanyang University Hospital during the period from 1992 to 1996. Using these cases, we analyzed their cumulative 5-year survival rate according to three kinds of staging systems; old UICC-TNM staging system (1987), new UICC-TNM staging system (1997), and the Japanese staging system for gastric carcinoma (1993). RESULTS: The follow up rate was 94.3% and the median follow up period was 30.3 months. All of these three systems showed a statistically significant survival difference according to their different classifications. When the distribution of stage between old and new UICC-TNM staging system was compared, 95 cases (20.1%) were subjected to stage shifting, which involves 12.1% of up-staging and 8.4% of down-staging. Stage shifting was most prominent in stage IIIb (68.8%). The cumulative 5-year survival rate according to the new UICC-TNM staging system was 99.1% in stage Ia, 81.4% in stage Ib, 75.2% in stage II, 45.9% in stage IIIa, 21.0% in stage IIIb, and 19.4% in stage IV. CONCLUSION: We conclude that the new UICC-TNM staging system is simple, practically convenient, and highly reproducible, and it showed a statistically significant survival difference according to their staging classification.