We describe the 4-year follow-up of an endocrine tumour of the pancreas (vipoma-glucagonoma) treated with chemotherapy. To control the endocrine syndrome we used somatostatin 14 by continuous subcutaneous infusion for 1 year, followed by the somatostatin analogue SMS 201-995 administered alone without antitumoral chemotherapy. Under SMS 201-995 (100 micrograms 12-hourly) the endocrine syndrome dramatically improved. This effect persisted for 12 months after which a relative resistance to the drug developed. It was necessary to increase the dosage (300-400 micrograms/24 hours) and to alter the mode of administration (continuous subcutaneous infusion) to obtain a clinical benefit inferior to that obtained during the first year of treatment with SMS 201-995. At present this drug is given combined with recombinant interferon alpha 2A. In spite of computerized tomography, ultrasonography and monitoring of hormone levels we were unable to determine whether or not SMS 201-995 exerted a partial antitumoral effect.