Influences of clotrimazole on the blood cholesterol and HDL-cholesterol level were studied in rats. Rats were provided food and water ad libitum and clotrimazole and methylcellulose were gavaged for 6 days. Clotrimazole was suspended in 1% methylcellulose solution as and administered at concentration 20mg/Kg, 40mg/Kg, 60mg/Kg. Body weight gain and liver weight/body weight ratio, serum cholesterol level, serum HDL-cholesterol level, serum triglyceride level, the activity of cytochrome p450 and erythromycin demethylase were determined at 6th day. Clotrimazole decreased the body weight gain a little as compared with control group and did not show any influence on liver weight/body weight ratio. Clotrimazole increased the serum HDL-cholesterol and serum triglyceride level significantly. Clotrimazole increased the microsomal cytochrome P450 significantly and increased the erythromycin demethylase (cytochrome P450 IIIA) significantly too. It might be conclued that clotrimazole showed a little influence on body weight and increased the serum lipid, especially HDL-cholesterol level. It also increased microsomal cytochrome P450 IIIA significantly. It might be concluded that clotrimazole showed a corelative influence between HDL-cholesterol and cytochrome P450 IIIA. In these results clotrimazole can be used as an anti-atherosclerotic agent by increasing the HDL-cholesterol but it is necessary that cloreimazole will show any adverse or side action on body or not.