The aim of our study was to evaluate the effects of diet induced hypercholesterolemia and associated atherosclerosis in rabbits on serum thromboxane B2 levels. We have determined thromboxane B2 in serum of hypercholesterolemic rabbits with atherosclerosis and in normocholesterolemic rabbits without atherosclerosis. Our data show only a mildly higher serum thromboxane levels in hypercholesterolemic rabbits and extensive atherosclerosis than in controls without atherosclerosis. In conclusion, these results show that diet induced hypercholesterolemia was not associated with thromboxane B2 generation, in spite of a diffuse experimental atheromatosis.