The author made a study of equine pituitary oil and compared it with equine cerebrol. Pituitary oil is a viscuous liquid with saponification value of 136.2 and iodine value of 93.4, while cerebrol is a solid having saponification value of 50.5 and iodine value of 56.6. Cholesterol content of the two are 1.84% and 18.4%, respectively, showing that that in pituitary oil is only 1/10 of cerebrol. Palmitic acid was isolated as a saturated fatty acid from pituitary oil, which seems to constitute majority of the component. Oleic acid was obtained as an unsaturated fatty acid and a number of oxidized acids of unknown origin were also obtained.