Subspecific differences were found in total and esterified cholesterol of Malayan tree shrews. Thirty-twoT. glis sordida (Tioman Island) had mean levels of 73.4 mg% total cholesterol and 50.6 mg% esterified cholesterol. Mean levels of 57.3 mg% total cholesterol and 38.2 mg% cholesterol esters were found in 25T. g. ferruginea from the Malayan mainland. Other factors such as sex, pregnancy, and perhaps stress as related to diet and density of population, appeared to contribute to the variance of cholesterol level between insular and mainland forms.