The cholesterol-fed rabbit is useful for atherosclerosis research. We describe development of a low-magnesium (Mg) cholesterol-containing diet to accelerate atherosclerosis in this model. Male New Zealand White rabbits were fed either chow or one of four atherogenic diets: 1% cholesterol 10% fat 0.11% Mg, 1% cholesterol 10% fat 0.40% Mg, 2% cholesterol 20% fat 0.11% Mg, or 2% cholesterol 20% fat 0.40% Mg. While feed intake decreased in cholesterol-fed rabbits, they were able to maintain their body weights. Rabbits consuming cholesterol experienced profound hypercholesterolemia and tissue lipid accumulation, with plasma cholesterol levels above 1500 mg/dl for all groups at the completion of the study. Liver and spleen lipid content and liver cholesterol content also increased. Aortic arch atheroma thickness was greatest in 1% cholesterol 10% fat 0.11% Mg animals. Tissue Mg levels decreased in cholesterol-fed animals compared to chow-fed controls, despite equal or greater serum Mg levels. Our results indicate that the 1% cholesterol 10% fat 0.11% Mg diet was optimal at promoting hypercholesterolemia and atherosclerosis while minimizing health complications for the animals. The low Mg cholesterol diet will be useful to other biomedical researchers interested in utilizing the rabbit for cardiovascular disease research.