The efficacy and safety of endoscopic therapy was investigated prospectively in 42 patients with 44 early gastric cancers who were not candidates for surgery. Thirty-five of the 44 lesions (80%) were treated by endoscopic therapy alone. Adequate tumor resection was possible in lesions less than 2 cm in diameter, in those of the protruding, flat, and erosive types, and in those located in the antrum. None of the 35 patients who were judged completely cured by the initial therapy developed recurrence or lymph node metastases in the follow-up period (range, 3-114 months; mean, 37 months). Therefore, endoscopic therapy appears effective in the treatment of patients with early gastric cancer when the risks of surgery are too high.