A 70-year-old male was admitted to our institution with a complaint of vomiting in mid-September 2011. Upper gastroendoscopy revealed an approximately 20 mm submucosal tumor in the anterior wall of the lesser curvature at the lower gastric body that was overlain by 15 mm type 0-I conglomerate lesion. Distal gastrectomy and reconstruction using Billroth I was performed in mid-November 2011. Gross specimen revealed an 18×18×10 mm elastic, hard submucosal tumor in the lesser curvature at the lower body, which was overlain by a 14×14×8 mm type 0-I conglomerate lesion. Hematoxylin and eosin staining of the submucosal tumor revealed spindle cells, positive for c-kit and CD34, but negative for desmin and S-100 proteins after immunochemical analysis; thus, an uncommitted type of gastrointestinal tumor (GIST) was diagnosed. Pathological analysis of the type 0-I lesion revealed a well differentiated tubular adenocarcinoma. There was no continuity between gastric cancer and GIST. His postoperative course was uneventful and the patient was discharged ambulatory 25 days after admission. This case represents a rare case of synchronous occurrence of early gastric cancer and GIST at the same site.