The primary elimination from circulating blood of intravenously administered endotoxin, and the primary distribution of the phagocytised endotoxin have been compared in warfarinpretreated and untreated rabbits. The results show that the elimination rate of endotoxin is significantly higher in warfarin-treated rabbits than in untreated. The difference is, however, small, and does not reflect a significant difference in the organ distribution although the amounts of endotoxin in the organs are somewhat higher in the warfarin-treated animals. Twenty min after injection about 75 per cent of the injected endotoxin has been eliminated from circulation, and about 50 per cent of the injected dose is located to the liver. The highest amount of endotoxin per g tissue is, however, found in the lungs. Twenty min after injection the same percentage, about 90, of circulating endotoxin was in both groups located to the plasma phase. The fact that the clearance rate of endotoxin in warfarin-treated rabbits in higher than in untreated rabbits is thought to be due to the existence of a competitive phagocytosis of endotoxin and fibrin clots and not to a changed endotoxinplatelet interaction.