Twenty-four patients with 26 apudomas have been treated with Sandostatin (octreotide) in Belfast. The 2 patients with vipoma showed an excellent response clinically and biochemically. Of 15 patients with carcinoids, Sandostatin improved the diarrhoea in 70%, flush in 58%, and wheeze in 100% of patients. Patients with insulinoma and the Zollinger-Ellison syndrome were unresponsive to Sandostatin. In general, the response to Sandostatin appeared to decline as the tumour size increased and tumour markers rose. Side effects have not been a problem.