BACKGROUND: Hepatic arterial chemoembolization (CE) with anthracyclines is an effective treatment for progressive liver metastases of digestive endocrine tumours. Streptozotocin (STZ) is widely used for systemic chemotherapy, but its efficacy by the hepatic arterial route has not been evaluated. PATIENTS AND METHODS: Fifteen consecutive patients, mean age 57.8 years, were prospectively included between July 1993 and January 1997. All patients had progressive liver metastases from either a carcinoid tumour (eight patients) or an islet cell carcinoma (ICC) (seven patients) that had increased in size (> or = 25%) before CE. Five patients had the carcinoid syndrome. STZ was administered, as an emulsion with iodized oil, into the hepatic artery before embolization with gelatin sponge particles. Two to six procedures (median, 3) were performed in 12 patients (one in three patients). Changes in the size of the liver metastases were evaluated by CT scan or MRI according to WHO criteria. The median follow-up was 15 months (1-50). RESULTS: An objective response was achieved in 8/15 patients (53%; median duration of 10.5 months) whatever the primary tumour (carcinoid or ICC). The carcinoid syndrome disappeared in 3/5 patients for 10, 11 and 17 months, respectively. CE effectively controlled hypoglycaemic attacks (decrease of > 50%) in the patient with insulinoma. The biological response was complete in four patients for a median duration of 7 months. CE induced minor side effects, namely nausea, fever and abdominal pain. Acute and reversible tubular necrosis due to CE was observed in one patient who had previously undergone a nephrectomy. CONCLUSION: Hepatic arterial chemoembolization with STZ is an effective treatment for patients with liver metastases caused by digestive endocrine tumours.