Malabsorption of fat and α-tocopherol was induced in rats by feeding cholestyramine and the effect of Tween 80 and Pluronic F 68 was assessed. Tween 80 did not influence the malabsorption of fat or α-tocopherol. Pluronic F68 did not change α-tocopherol absorption but did significantly improve fat absorption. The proportion of radioactivity remaining in the liver 5 days after a labelled dose of α-tocopherol was increased when Tween 80 or Pluronic F68 was present, perhaps indicating increased absorption via the portal vein. Serum cholesterol levels were not affected by the different diets. The greatly increased excretion of faecal bile salts on dietary cholestyramine was unchanged by the detergents.