A study on the relation of plasma- and RBC-tocopherol to plasma lipids and adiposity led to the following findings. Plasma tocopherol increased in parallel with increased plasma total lipid and beta-lipoprotein levels, while RBC tocopherol levels had little correlation with those of plasma lipids or beta-lipoproteins. The RBC-to-plasma tocopherol ratio decreased with increased plasma lipids and beta-lipoproteins. Though the relations of HDL-cholesterol, total lipids and beta-lipoproteins to RBC tocopherol levels resembled each other, those of HDL-cholesterol to plasma tocopherol levels and RBC-to-plasma tocopherol ratios differed greatly from the relationship in total lipids and beta-lipoproteins, especially the RBC-to-plasma ratios which had no definite pattern. Plasma tocopherol was unrelated to obesity grade, while the RBC tocopherol and RBC-to-plasma ratios decreased with increased obesity.