Ablation of renal arteriovenous malformations with absolute alcohol was performed in seven patients with massive hematuria. In three patients, total occlusion of the malformations was accomplished by ablation of two arterial branches. In the remaining four patients, the malformations were partially occluded by ablation of one or two arterial branches. In addition to ablation with alcohol, two of the four patients underwent subselective embolization with Gelfoam (absorbable gelatin sponge) under epinephrine pharmacoangiography, which resulted in the disappearance of the remaining malformations. None of the patients had serious complications from ablation with alcohol, although dyspnea and headache occurred in one patient with marked arteriovenous shunting. During long-term follow-ups, hematuria disappeared in six patients. In the remaining patient hematuria recurred but did not require treatment. These data suggest that alcohol ablation is useful and safe in the treatment of renal arteriovenous malformations.