The results of surgical treatment of patients with advanced gastric cancer were analyzed retrospectively in terms of the extent of dissection of lymph nodes. The postoperative 5-year survival rate was 50.3% for 160 patients who had undergone potentially curative surgery with dissection of group 1, 2, and 3 lymph nodes (R3), compared with 48.8% for 185 patients with dissection of group 1 and 2 lymph nodes (R2). There was no difference in terms of survival between the two groups of patients. Of 160 patients receiving R3, 19 (11.9%) were found to be positive for metastasis to group 3 lymph nodes, and only 5 survived for more than 5 years after surgery (postoperative 5-year survival rate of 26.3%). In four of these five patients, metastases in the group 3 lymph nodes were confined to nodes in the hepatoduodenal ligament. Thus, it appears that in dissection of the deepest nodes, lymph nodes in the hepatoduodenal ligament are the most important to remove in the surgical treatment of advanced gastric cancer.