The anatomic distribution, size, and histologic mode of involvement of 98 metastatic lymph nodes in 49 of 370 patients were examined to determine to what extent lymphadenectomy should be performed in addition to gastrectomy in patients with early gastric cancer. Nodal involvement in the marginal sinus (30 nodes) and partial medullary sinus (37 nodes) were commonly seen, and the lymph nodes of those types were enlarged compared with 1,086 patients with no metastatic lymph nodes (control group). Lymph nodes of the wide medullary sinus (11 nodes), small nodule (3 nodes), and massive involvement types (17 nodes) did not enlarge compared with those of the other types and those of the control group. Most of the metastatic sites (76.6 percent) were in the perigastric lymph nodes along the lesser and greater curvatures, about a fifth were in the extraperigastric nodes along the left gastric, common hepatic, celiac, and splenic arteries, and the least were in the extraperigastric nodes (3.1 percent) along the hepatoduodenal ligament. Since the rate of macroscopic diagnosis during operation was so poor, regardless of the histologic modes of nodal involvement, and also in cases of metastatic lymph nodes less than 15 mm in widest diameter, for curative operation of patients with early gastric cancer, perigastric and extraperigastric lymph nodes along the main arteries near the stomach should be completely dissected, in addition to resection of the stomach.