Neuroendocrine tumors (NETs) are relatively rare and comprise carcinoids, gastrinomas, and poorly differentiated endocrine carcinomas (PDECs). Diagnostic procedures should include endoscopy with biopsy, computed tomography, or magnetic resonance imaging. Fluorodeoxyglucose positron-emission tomography is also useful for the detection of extraabdominal metastases. Complete resection with lymph node dissection, as recommended for other cancers, such as distal gastrectomy, total gastrectomy, and pancreaticoduodenectomy, should be attempted in localized NETs. Endoscopic submucosal dissection should also be attempted in early-stage disease. Both curative and palliative surgery is indicated for patients with liver metastases of foregut-origin NETs. Combination chemotherapy (cisplatin/carboplatin + etoposide) may be useful in treating PDECs with metastases. Combination therapies with streptozotocin, doxorubicin, and 5-fluorouracil are also useful for the treatment of carcinoid tumors. Somatostatin analogues, such as octreotide and SOM 230, have been registered for the control of hormonal symptoms in patients with gastrointestinal NETs.