In the procedure of Van Handel and Zilversmit (1), triglycerides are measured by assay of glycerol, after removal of phospholipids. Some modifications of this method are given. Zeolite is ground to 80 mesh (2); the unsaponified values are replaced by a simple reagent blank; oils are purified before being used as standards. Eight separate extractions from a single serum specimen, assayed in quadruplicate, yielded a value of 1.01 mg./ml. with a standard deviation of 0.028 mg./ml. for the 32 determinations.