The study and treatment of carcinoid syndrome have both made significant strides in recent years. New studies on its epidemiology show an increasing occurrence; increasing insights into the pathogenesis of its various clinical manifestations and into its natural history; the definition of prognostic factors; the introduction of new methods for confirming its presence; the creation of new drugs for treating its various manifestations, both initially and in somatostatin-refractory cases; and an overall better understanding of the disease's origins, course, and treatment options. These developments have led to a number of controversies, which are also discussed.