The present study examined the effects of Se, vitamin E and combined Se and vitamin E deficiencies in rats on plasma lipid, lipoprotein and apolipoprotein (ape) concentrations. Deficiencies were induced by feeding rats the respective diets for 6 weeks. The study shows that Se deficiency results in increased concentrations of plasma cholesterol and ape E. Both could be explained by an increase in the HDL1 fraction. Vitamin E deficiency alone had no significant effect on plasma lipid, lipoprotein and ape concentrations. Se deficiency in combination with vitamin E deficiency leads to an increase in plasma LDL and apo B concentrations. These results point to the need for further investigations on the mechanism by which Se deficiency affects lipoprotein metabolism.