We analyzed 30 endoscopically treated patients with early gastric cancer in terms of the utility of endoscopic ultrasonography (EUS) and the evaluation of prognosis. Endoscopic therapy for early gastric cancer included strip biopsy, laser irradiation, and OK-432 injection. Examination of the depth of cancer invasion in the strip biopsy specimens showed that the diagnostic accuracy of EUS was 85.7%. Complete resection rate in strip biopsy was 82.8%, and the patients with incompletely resected cancer were successfully treated with laser irradiation and/or OK432 injection. The prognosis of the patients treated with strip biopsy was good. Three patients died of causes other than gastric cancer. Local recurrence and a heterochronous new lesion developed in six patients, but all of these cases were successfully treated with additional strip biopsy. All but one patient treated with laser irradiation and/or OK 432 injection survived during the study period. These results suggest that EUS is useful in determining the indication of endoscopic therapies and that prognosis is good in patients with early gastric cancer treated endoscopically.