ABSTRACT: The effect of dietary high amylose cornstarch (HACS) on plasma lipids was studied in ovariectomized rats (OVX-rats). OVX-rats were fed cholesterol-free purified diets containing either 0%, 5%, 10%, 20%, or 30%HACS as a percentage of total carbohydrate for 28 d. Plasma triacylglycerol (TAG) concentration and apparent starch digestibility were found to decrease as the dietary level of HACS increased. On the other hand, the amount of small intestinal bile acids, cecal tissue weight, the amount of cecal short-chain fatty acids, primary:secondary ratio of fecal bile acids, and fecal weight were found to increase. However, plasma total cholesterol concentration, excretion of fecal bile acids, cholesterol 7α-hydroxylase activity, liver lipids, body weight gain, liver weight, and the weight of cecal contents were not affected by the diets. The amount of propionic acid in the cecal content increased as the dietary level of HACS increased. HACS might lower lipogenesis in liver and adipose tissue and lower very low density lipoprotein secretion by increasing propionic acid production, consequently leading to a decreased plasma TAG concentration.