PURPOSE: Advanced gastric cancer that invades the subserosa can be classified into three subgroups according to the tumor cell growth patterns: expansive growth (ss alpha), infiltrative growth (ss gamma) and intermediate growth (ss beta). Serosal invasion is a well-known risk factor for peritoneal recurrence. It has been reported that the risk of peritoneal seeding of ssgamma is comparable with serosal tumor, although tumor cells do not actually reached the serosa as one of the histologic findings. In this study, the clinicopathologic features of subserosal tumors according to the growth pattern were analyzed. METHODS: One hundred and twenty-nine patients who underwent a gastrectomy for gastric cancer invading the subserosa at the Department of Surgery, Kangnam St. Mary's Hospital, The Catholic University of Korea, between 1994 and 1998, were retrospectively evaluated. No patients had any other organ tumor. The patients were divided into two groups: 86 non-infiltrative cancers (Group I, ss alpha and ss beta) and 43 infiltrative cancers (Group II, ss gamma) according to the tumor growth pattern. RESULTS: Undifferentiated carcinomas were more frequent group II than group I (83.7% vs. 27.9%, P=0.000). There was no difference in any of the other clinicopathological characteristics between the two groups, including age, gender, tumor size or lymph node metastasis. However, the recurrence patterns were significantly different between the two groups. The peritoneal recurrence rate was higher in group II than group I (71.4% vs 39.3%, P=0.036). The 5 and 10-year survival rates were 66.9 and 61.2% for group I and 50.4% and 40.4% for group II, respectively (P>0.05). CONCLUSION: A high incidence of peritoneal recurrence was noted in the infiltrative subserosal gastric cancer. Therefore, attention should be focused on the diagnosis of peritoneal recurrence during follow-up for this subtype of subserosal cancer.