Carcinoid tumors secrete many different types of substances (e.g. serotonin, bradykinin) that may produce potentially fatal intraoperative reactions such as hypotension and bronchoconstriction. The most effective treatment for the deleterious cardiovascular and pulmonary effects of serotonin and bradykinin is octreotide, a somatostatin analogue. Carcinoid heart disease, which develops in the majority of patients with carcinoid syndrome, presents the anesthesiologist with more diagnostic and therapeutic dilemmas.The incidence of carcinoid tumors is much greater than previously recognized. New diagnostic techniques permit identification and localization of carcinoid tumors with greater accuracy. Short term and long term therapy with octreotide significantly improves survival and reduces the severity of 'carcinoid crises'. Echocardiographic studies have demonstrated a very high incidence of carcinoid heart disease (tricuspid and pulmonary insufficiency) in patients with carcinoid syndrome. Cardiac valve surgery is, consequently, becoming much more common in patients with carcinoid syndrome.More patients with carcinoid tumors and carcinoid syndrome are requiring anesthesia and surgery. Specific therapy with somatostatin analogues (octreotide) has replaced older less specific drugs (e.g. antihistamines) for the treatment of adverse effects caused by products of carcinoid tumors.