Experiments were performed to compare the effects of cholesterol feeding in ( a ) control rabbits, ( b ) alloxan-diabetic rabbits, and ( c ) rabbits injected with alloxan while the pancreas was temporarily occluded from the circulation. The alloxan-diabetic rabbits consumed significantly higher quantities of cholesterol and food and had serum cholesterol and lipoprotein ( S f 5–9 and S f 16–30) concentrations significantly increased over the control levels. They failed to show a commensurate increase in the degree of atherosclerosis. Rabbits in which the diabetogenic action of alloxan was prevented by temporary occlusion of the pancreas from the circulation during its administration developed grades of hypercholesterolemia, hyperlipoproteinemia, and atherosclerosis not significantly different from the controls. The results are interpreted as indicating that the effects of alloxan on tissues other than the pancreas do not protect against experimental atherosclerosis produced by cholesterol feeding.