At present there is no established therapy for treating patients with hereditary hemorrhagic telangiectasia (HHT) and symptomatic hepatic involvement. We present the results of a prospective study with 15 consecutive patients who were treated with staged hepatic artery embolization (HAE). Branches of the hepatic artery were selectively catheterized and embolized in stages using polyvinyl alcohol particles (PVA) and platinum microcoils or steel macrocoils. Prophylactic antibiotics, analgesics and anti-emetics were administered after every embolization. Clinical symptomatology and cardiac output were assessed before and after therapy as well as at the end of follow-up (median 28 months; range 10-136 months). Five patients had abdominal pain and four patients had symptoms of portal hypertension. The cardiac output was raised in all patients, with cardiac failure being present in 11 patients. After treatment, pain resolved in all five patients, and portal hypertension improved in two of the four patients. The mean cardiac output decreased significantly ( P<0.001) from 12.57+/-3.27 l/min pre-treatment to 8.36+/-2.60 l/min at the end of follow-up. Symptoms arising from cardiac failure resolved or improved markedly in all but one patient. Cholangitis and/or cholecystitis occurred in three patients of whom two required a cholecystectomy. One patient with pre-existent hepatic cirrhosis died as a complication of the procedure. Staged HAE yields long-term relief of clinical symptoms in patients with HHT and hepatic involvement. Patients with pre-existing hepatic cirrhosis may be poor candidates for HAE.