Somatostatinomas are endocrine tumors with predominant secretion of somatostatin. The majority occur in the pancreas and the duodenum. However, distinctive clinico-pathologic features are reported for both of them. The features of pancreatic somatostatinomas are a larger size, a more frequent clinical expression, a female predominance and a poorer prognosis. Duodenal somatostatinomas are characterized by psammoma bodies at histologic examination. We report here two cases of pancreatic and ampullary somatostatinomas, focusing on the main diagnostic problems and on the characteristics of each tumoral localization.