Neuroendocrine neoplasms (NEN) occur in the entire gastrointestinal tract. The updated classification of the WHO (2010) and current TNM-classification provide a basis for the therapeutic decision and assess the prognosis. Endoscopy and different imaging techniques are important for the localization of the primary tumor as well as local and distant metastases. The most important diagnostic imaging technique is somatostatin receptor scintigraphy. Therapeutic strategy should be discussed within the scope of a multidisciplinary tumor board. Surgery of NEN is the sole curative option. The treatment options for liver metastases include surgical resection as well as radiofrequency ablation and hepatic artery embolization. In advanced stage, systemic therapy should be used. Recent studies demonstrated a significantly prolonged progression-free survival using octreotide in well differentiated NEN. Besides the well established steptozotocine based chemotherapy regimens for pancreatic NEN, novel agents such as the mTOR-inhibitor everolimus and multityrosine kinase inhibitor sunitinib have recently also shown a prolonged progression-free survival. Moreover, temozolomide-based chemotherapy appears to be effective in pancreatic NEN. Finally, somatostatin receptor targeted radionuclide therapy can be effective in progressing gastroenteropancreatic NEN.