PURPOSE: To evaluate the embolic effect and pathologic change in the kidney after infusion of 50% acetic acidin the renal artery. MATERIALS AND METHODS: Five kidneys were embolized with 50% acetic acid mixed with saline(group A) and five were embolized with 50% acetic acid mixed with contrast medium (group B). Four rabbits(2 fromgroup A and 2 from group B) were sacrificed during the first day and the remaining six, 28 days afterembolization. To determine the effect of embolization and pathologic findings, the two groups were compared. RESULTS: Complete occlusion of the renal artery was observed in both groups; histologic findings indicatingtubular necrosis and blood clots within the renal artery were noted one day after embolization. After four weeks,complete necrosis of the renal arterial wall and tubular cells had occurred. The procedures required forembolization were easier in group B because the extent of embolization could be controlled by fluoroscopy. CONCLUSION: At 50% dilution after mixing with contrast medium, the embolie effect of acetic acid isperfect;because the embolic material is visualised the procedure was easier to control than embolization withalcohol. acetic acid can, threrfore, be used as an effective embolic agent in renal artery embolization.