Increased plasma levels of fibrinogen are associated with a higher risk of cardiovascular disease. It has been suggested that lipid levels may influence the fibrinogen levels by a mechanism other than the synthesis rate, for example a decreased clearance rate. We performed a pilot study to explore this possibility. Twelve male Wistar rats were red for four weeks with a control low fat/low clolestorol diet, a high fat/high cholesterol diet, and a high fat/high cholesterol diet with an additional 0.5% cholic acid. Labeled I-125 fibrinogen was Injected, and Mood was sampled repeatedly. From the plasma radioactivity of the samples, fibrinogen halflife time was calculated for each animal. Our results suggest that plasma lipids lengthen the fibrinogen halflife times, although the differences were not statistically significant in this small study. Our final conclusion from this study is that lipids may have an effect on the turnover rate of fibrinogen and possibly affect fibrinogen levels through this mechanism.