AbstractThis paper reports the differences in the fecal excretion of cholesterol and its degradation products in high‐and low‐responding rhesus monkeys fed diets with and without extra cholesterol. The high‐responding monkeys had a great increase in plasma cholesterol concentration when fed a high‐cholesterol diet, whereas the low‐responders had a small increase when fed the same diet. The results show that low‐responding monkeys, when fed high‐cholesterol diets, excrete nearly two to three times the amount of cholesterol and its bacterial degradation products in the feces than the high‐responding monkeys. We suggest that these two select groups of monkeys may be useful models for the study of the role cholesterol and its bacterial degradation products play in colon cancer.