Gastroenteropancreatic (GEP) neuroendocrine tumors (NETs) are relatively rare neoplasms that characteristically synthesize and secrete an excess of a variety of regulatory peptides, hormones, and neuroamines, which regulate gut and pancreatic function. This excess can lead to distinct clinical syndromes. Therapeutic strategies include surgery, radiofrequency ablation, chemotherapy, chemoembolization, and biotherapy using somatostatin analogs. The clinical syndromes and the various management strategies can lead to altered gut and pancreatic function with nutritional consequences. Diet and nutritional management is critical for GEP NET patients and is the focus of this article.