Embolization for ablation of organs and tumor infarction requires uniform permanent occlusion of the distal vasculature. This is best accomplished through the use of solidifying liquids. The study on 15 dogs reported here compares the degree of peripheral vascular embolization and its relation to tissue infarction both acutely and chronically following embolization of the renal arteries with two solidifying liquids, a low viscosity silicone and the occlusion gel Ethibloc. Silicone produced quite uniform distal distribution including 50 to 80% (mean 66%) of renal glomeruli, whereas Ethibloc occluded more proximally and reached only 10 to 50% (mean 22%) of all glomeruli. After three months complete cortical infarction of all nine kidneys embolized with silicone was found, whereas two of the three kidneys embolized with Ethibloc retained nests of viable glomeruli. Balloon occlusion of the entire renal artery inflow during embolization prevented distal venous emboli whereas partial inflow occlusion allowed systemic venous embolization. It is concluded that due to its more uniform distal penetration low viscosity silicone is a more suitable embolization agent than Ethibloc for organ ablation. Total arterial inflow occlusion during embolization effectively prevents systemic venous embolization.