Neuroendocrine tumors are rare neoplasms. In most cases conventional imaging techniques (US,CT,RMN) are not able to identify primitive tumors. This fact conditions the approach to the treatment of these tumors. 111In-Pentetreotide scintigraphy (Octreoscan) permits to visualize occult primary tumor by somatostatin receptors, changing the clinical history of patients. This method can be used in guided surgery with a hand-held gamma probe allowing to improve the detection of occult tumor (inverse square law), giving to the patient further possibilities of survival. Intraoperative gamma probe was still utilized with success in the management of other tumors, as relapsed colorectal cancer, while reports about gamma probe in neuroendocrine tumors are poor because of the rarity of disease. In two cases we have utilized a gamma probe (ORIS model 2) in neuroendocrine tumors: in a case we have observed liver recurring localizations originating from pancreas, with high proliferative index (Ki-67 = 2033 x 10 HPF), and in a case liver metastatic carcinoid of lung. The difference between tumor and background counts was significant exceeds 2 standard deviation count rate. Gamma probe permits a radical cure in many cases and completes intraoperative ultrasound in order to provide the surgeon with other information on the intraoperative staging of the patient.