Endoscopic ultrasonography is a new imaging technique which has previously demonstrated its accuracy in localization of small pancreatic cancers. The aim of this retrospective study was to report our experience of this new method for localization of small endocrine tumors of potential pancreatic origin. Thirteen patients with insulinoma and 17 patients with Zollinger-Ellison syndrome were studied. All were imaged in a reference center by ultrasound (US) and CT scan (CT) before endoscopic ultrasonography. Insulinomas: 78.5% of tumors were 15 mm or less in size. The endoscopic ultrasonography was more accurate (79%) than US (7%) and CT (14%) for localization of the 14 tumors removed in the 13 patients who underwent surgery. Gastrinomas: Endoscopic ultrasonography was able to image 7 to the 9 pancreatic gastrinomas, the 2 duodenal gastrinomas, and the 2 gastrinomas located in peripancreatic lymph nodes which were removed in the 9 patients who underwent surgery. US and CT were able to image only one of the two peripancreatic lymph nodes. We concluded that endoscopic ultrasonography is a highly accurate tool for localization of small pancreatic endocrine tumors and should be performed early in the management of these tumors.