The effect of two edible mushrooms, namely Auricularia auricula (Tree-ear) and Tremella fuciformis (White jelly-leaf) of the Heterobasidiae, on serum and liver lipids, fecal neutral steroids and bile acid excretion was investigated in rats. Male Sprague-Dawley rats were fed two semisynthetic hypercholesterolemic diets (1.5% cholesterol, 5% fat) each containing 5% dried powder of the two mushrooms. After 4 wk of mushroom diet consumption, the serum total cholesterol concentration was significantly decreased in both A. auricula and T. fuciformis diet groups (17 and 19%, respectively). Similar significant decrease in serum LDL cholesterol level was observed (24 and 31%, respectively). There was no significant difference found in serum HDL cholesterol concentration and the amount of liver total cholesterol and total lipids among the two mushroom diet groups and the control group. Only animals fed T. fuciformis diet had a significant decrease in serum triacylglycerol level. Animals fed A. auricula diet had a significant increase in the levels of fecal neutral steriods and bile acids by 39 and 46%, respectively. T. fuciformis diet also increased significantly the fecal excretion of neutral steroids and bile acids in rats by 51 and 36%, respectively. In the present study, both mushrooms had effective hypocholesterolemic activity in rats.