Octreotide is an investigational synthetic peptide exhibiting actions similar to those of endogenous somatostatin. It has a longer half-life than the native hormone and can be administered by subcutaneous injection. Octreotide inhibits the secretion of growth hormone and numerous regulatory peptides of the gastroenteropancreatic system. Trials evaluating the clinical utility of octreotide indicate efficacy in the management of symptoms associated with acromegaly and hypersecretory neuroendocrine tumors, and in the control of nontumoral secretory diarrheas. Octreotide therapy is well tolerated. This agent should prove useful in the symptomatic control of a number of rare hypersecretory disorders.