AbstractHyperlipidemia was induced in rats by feeding them cheese mixed with high levels of cholesterol. Triglyceride levels more than doubled from 70.4 ± 25.8 mg/dl before the diet to 160.1 ± 50.5 mg/dl three weeks after initiation of the diet, and cholesterol levels were increased by approximately 25% from 72.5 ± 8.1 mg/dl to 98.9 ± 18.5 mg/dl after three weeks of the diet. The effects of microsurgically created side‐to‐side and end‐to‐side portacaval shunts were then studied. Triglyceride levels were lowered to normal after either type of shunt (68.4 ± 19.2 mg/dl in the side‐to‐side group and 58.1 ± 25.7 mg/dl in the end‐to‐side group) by four weeks after the creation of the shunt. Cholesterol levels tended to be slightly lower after either type of portacaval shunt, but did not return to normal. The mechanism by which the portacaval shunt reduced elevated triglyceride levels and, to a lesser extent, cholesterol levels is not clear, but hyperlipidemia induced by a high cholesterol diet in rats should be a useful model for further s