Bacgrounds/Aims: This study was performed to investigate the clinicopathologic features and the usefulness of the endoscopic treatment for early colorectal cancer (ECC). Methods: Clinical and pathological features of 101 lesions in 94 patients with ECC were retrospectively analyzed. Results: Submucosal invasion was more common in the superficial type (1 1/18) than in the protruded type (26/83). It was observed in 20.9% of patients with well differentiated adenocarcinomas, in 66.7% of patients with moderately differentiated adenocarcinomas, and in 100% of patients with poorly differentiated adenocarcinomas, Of the 62 specimens resected surgically, none of 33 patients with mucosal carcinomas revealed lymph node metastasis. Of the 29 patients with submucosal invasion, 11 patients satisfied good prognostic criteria (i.e. superficial submucosal lesion, well or moderately differentiated adenocarcinoma, and no evidence of lymphatic or venous invasion) and none of them showed lymph node metastasis. On the other hand, 18 patients had one or more poor prognostic factors and 4 of them (22.2%) showed lymph mode metastasis. All of 5 patients with submucosal carcinoma resected endoscopically fulfilled good prognostic criteria. Four of them are alive without recurrence during the follow-up period ranging from 20 to 59 months (median 33 months), and one patient died of unrelated illness. Conclusions: These results suggest that endoscopic treatment might be sufficient for mucosal ECC or submucosal ECC with good prognostie criteria, (Kor J Gastroenterol 1998;32:475 - 483)