Small-bowel submucosal tumors (SMTs), such as GI stromal tumors, are difficult to diagnose before surgical treatment. If the SMT is diagnosed as a benign tumor before treatment, it can be followed-up without surgery. An SMT 13 mm in diameter was found in a 61-year-old man in the middle jejunum during a double-balloon endoscopy (DBE) performed to explore the cause of enteritis. The enteritis was cured by conservative therapy, but the SMT remained at the follow-up DBE 10 months later. EUS during DBE revealed that a heterogeneous hypoechoic mass originated from the third layer, including the anechoic portion. An ectopic pancreas was suspected but not definitively diagnosed. To more accurately diagnose the SMT, a partial EMR was performed at the time of the DBE. A post-EMR ulcer was closed by using hemoclips (Fig. 1) (Video 1, available online at www.giejournal.org). No adverse events were observed. Histopathologic examination revealed excretory ducts. The SMT was diagnosed as ectopic pancreas, based on EUS and histopathologic findings, and it was decided that the lesion should be followed without surgery. The partial EMR technique is useful for the management of patients with an undiagnosed SMT in the small bowel, although it presents a risk of bleeding.