OBJECTIVE The purpose of this study was to evaluate the frequency of lymph node metastasis according to the depth of tumor infiltration of the mucosa and submucosa. BACKGROUND DATA Currently some endoscopists extend the indication for endoscopic mucosal resection in gastric cancer to the submucosa. However, the decision between endoscopic mucosectomy or gastrectomy with lymphadenectomy for early gastric cancer depends especially on the probability of lymph node metastasis. METHODS One hundred twenty-six patients either had subtotal resection (n = 29) or total gastrectomy (n = 97) for T1 gastric cancer. The median number of resected lymph nodes was 21 (1-63). In the histopathologic analysis of the specimens the tumors were differentiated according to their wall penetration in the upper (m1), middle (m2), lower (m3) third of the mucosa or submucosa (sm1, sm2, sm3). The greatest diameter of the lesions, the Grading and the Goseki-, Ming-, WHO-, and Laurén classification were determined. RESULTS Patients with m1 (n = 3) and m2 (n = 5) layer infiltration had no lymphatic metastasis compared with 13% for m3 (n = 39). The rate of lymphatic metastasis in submucosal carcinomas was 21% for sm1 (n = 29), 16% for sm2 (n = 23) and 40% for sm3 (n = 25). Carcinomas with papillary differentiation, Grading G1 or <1 cm in diameter had no lymph node metastasis. The size of tumor <2 cm or > or =2 cm showed independent influence on the rate of lymph node metastasis. CONCLUSIONS Endoscopic mucosectomy in m3 carcinoma is questionable and in all submucosal carcinomas and lesions > or =2 cm it is not indicated.