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PNETs are classified into two entities, i.e., hormone-secreting and nonfunctioning tumors. Localization of small hormone-secreting symptomatic PNETs is sometimes difficult, while nonfunctioning PNETs are easy to identify. Arterial stimulation and venous sampling is quite useful to localize such tumors. Large nonfunctioning PNETs are often malignant and those larger than 10mm should be resected. The author has experienced an 8-mm nonfunctioning PNET accompanied by lymph node metastasis. Surgical resection provides the only chance for cure, including enucleation, segmental or left pancreatectomy, and pancreatic head resection. These procedures can be performed even under laparoscopy, although laparoscopic pancreatic head resection and pancreatoduodenectomy are still in the investigational phase and should not be applied to gastrinoma. Cytoreduction or debulking surgery may be performed in metastatic cases. Somatostatin analogues, especially the long-acting one, are useful to control symptoms. The mTOR inhibitor RAD001 seems to be an effective antitumor agent, preferably in conjunction with somatostatin.