Abstract The procedures described make it possible to determine chylomicron counts and one of the other lipid constituents on approximately 100 µl. of blood serum. In general, the technics used are those of Bessey and Lowry. Chylomicron counts are determined by a modification of the method of Becker, Meyer, and Necheles. Dilutions of high count serum are made with fasting serum and a correction made for the chylomicrons in the diluting serum. In each of the chemical mehods, 75 µl. of blood serum is used and the lipids completely extracted from the serum with alcohol-ether mixture. The method for fatty esters is an adaptation of the methods of Hill, and Bauer and Hirsch and involves the formation of a lavender-colored complex of ferric hydroxamate on the addition of an acidified solution of alcoholic ferric perchlorate. The method for lipid phosphorus is an adaptation of the macro method described by Hawk, Oser, and Summerson. The extracted lipids are oxidized with sulphuric acid and hydrogen peroxide and the phosphate present determined by the Fiske and Subbarow method. The method for cholesterol is an adaptation of the methods of Kibrick, et al. and Abel, et al. It involves the hydrolysis of cholesterol esters with 17% benzyl trimethylammonium hydroxide during the evaporation of the alcohol-ether extract and the use of the residue directly for the development of a green color by the Liebermann-Burchard reaction. The average fasting value for fatty esters obtained for 12 normal weight college women was 414 mg. per 100 ml., expressed as tripalmitin. For lipid phosphorus the average fasting value obtained for 8 normal weight college women was 7.8 mg. per 100 ml. The average fasting cholesterol value obtained for 16 normal weight college women was 154.8 mg. per 100 ml. The average value for 6 normal weight older women (ages 37-63) was 257.2 mg. per 100 ml.