Neuroendocrine tumors (NETs) are a heterogeneous group of malignancies that originate from neuroendocrine cells in various organs. NET can occur in different organs of the body, with gastrointestinal tract and pancreas being the most common primary sites. Its prognosis depends on several clinicopathological factors such as the primary tumor site, tumor burden, stage at diagnosis, metastasis, and tumor grade. Recently WHO classification was newly revised which subclassified grade 3 neuroendocrine carcinoma into well differentiated grade 3 neuroendocrine tumor and poorly differentiated grade 3 neuroendocrine carcinoma. With recent serial successes in large randomized phase 3 trials, more therapeutic options are now available for unresectable or metastatic pancreatic NETs (pNETs); lanreotide (somatostatin analogue), everolimus and sunitinib. Despite there is still lack of evidences based on large randomized phase 3 trial, cytotoxic chemotherapy such as temozolomide plus capecitabine and peptide receptor radionuclide therapy (PRRT) are also considered as one of promising therapy for advanced pNET patients.