This study was carried out on the male adult Wistar-Albino rats in order to investigate the effects of coffee and caffeine consumption on serum lipids in atherogenic and normal diets. Fifty rats were divided into five groups and each group was fed with the following diets: first group was a control group and fed with the standard chow diet, coffee, caffeine, cholesterol and cholesterol plus coffee were added to second, third, fourth, and fifth groups, respectively. The results indicated that the consumption of coffee alone had no effect on serum lipids. However the addition of coffee to a hypercholesterolemic diet significantly increased the effect on serum total cholesterol (P < 0.01), triglycerides (P < 0.05), VLDL-cholesterol (P < 0.05), LDL-cholesterol (P < 0.01), and HDL-cholesterol (P < 0.01) levels. Adding caffeine to normal diet resulted in an increase in serum total cholesterol (P < 0.01). Despite these increases, the ratio of HDL-cholesterol to total cholesterol and LDL-cholesterol remained unchanged. The results indicated that coffee could not be considered alone as a risk factor for coronary heart disease.