Neuroendocrine tumors are relatively rare. An estimated 25,690 new cases of thyroid cancer will be diagnosed in the United States in 2005, accounting for approximately 1% of all malignancies. Neuroendocrine tumors can be broadly subdivided into tumors that are benign or malignant, functional (i.e., producing a syndrome of hormonal excess) or nonfunctional. The management of neuroendocrine tumors with surgical, medical, or radiation therapies is determined by the specific endocrine glands involved, aggressiveness and stage of the tumor, hormonal concentrations detected, and specific patient needs. These guidelines have been designed to address scenarios presented by 80% of patients and to avoid scenarios relevant to less than 5% of patients. © Journal of the National Comprehensive Cancer Network.