A case of renal arteriovenous fistula (A-V fistula) treated by transcatheter embolization using absolute ethanol is reported. The catheter was superselectively placed in the proximal renal artery supplying cirsoid vessels and 15 ml of absolute ethanol was injected into the renal artery at a rate of 1 ml per second. Ten minutes after injection, complete occlusion of the fistula was confirmed. The postembolization syndrome was mild, particularly back pain and fever were mitigated. Repeat arteriogram after 3 months demonstrated persistent occlusion of the fistula. From this experience and a review of the literature, we postulate that the advantages of therapeutic embolization with ethanol for A-V fistula compared with other embolization techniques are the following: (1) persistence of arterial occlusion extending to the peripheral vessels, (2) less frequent possibility of recanalization and collateral formation, (3) less systemic toxicity even if ethanol has escaped into the systemic circulation through A-V fistula, and (4) no danger of accidental embolization of other arteries. Herein, we also review briefly the literature concerning both mechanism and feature of action of ethanol injected into the artery.