Octreotide, a long-acting somatostatin analogue has recently been introduced in the therapy of gastroenteropancreatic endocrine tumors, but home experience has been lacking. With the aim of drawing attention to this therapeutic possibility, a case of malignant carcinoid syndrome treated with octreotide for 18 months is reported. Despite the therapeutic attempts preceding the octreotide administration a gradual progression in clinical symptoms was observed and cardiac failure due to fibrotic and valvular heart disease developed. Cytotoxic chemotherapy, serotonin antagonists or repeated selective embolisation of the hepatic artery only resulted in a short transitional improvement. Octreotide in a dose of 100 micrograms three times daily by subcutaneous injection provided effective and rapid relief from episodic flushing and serious diarrhoea. Plasma level of serotonin and 24-hour urinary excretion of 5-hydroxyindolacetic acid decreased from 6 micrograms/ml to 2 micrograms/ml and from 800 mumol/day to 70 mumol/day, respectively. No changes in the number and extension of liver metastases could be seen after introducing the octreotide treatment. The patient's compensated cardiac status could be preserved and continuous therapy provided an acceptable quality of life.