The value of sequential percutaneous hepatic artery embolization with polyvinyl alcohol particles was examined in 22 patients with islet cell carcinoma metastatic to the liver. Nine patients had gastrinoma, 2 had glucagonoma, and 11 had no discernible hormonal secretions or syndromes. Ninety-seven embolizations were done with a median number of 4 (range, 1 to 12) per patient. The interval between embolizations ranged from 1 to 8 months. Twelve of twenty evaluable patients had a partial remission, frequently associated with subjective improvement and decrease in hormone levels. The projected median survival of all 22 patients from the initiation of embolization is 33.7 months (range, 1 to 72). Nausea, vomiting, fever, and abdominal pain occurred with each embolization and subsided usually by day 10 (range, 3 to 35). Sequential hepatic artery occlusion is an effective method for prolonged palliation in this selected group of patients.