Vein graft atherosclerosis is a common and serious complication of coronary artery bypass grafting (CABG). There is mounting evidence that lipoprotein abnormalities play an equally important role in the development of lesions in saphenous vein grafts after CABG as in native coronary vessel disease. The potential benefit of low-dose lipid lowering combination therapy in these patients has not been investigated. In a randomized, double-blind, placebo-controlled study, we compared the efficacy and safety of a low-dose combination of colestipol 10 g and simvastatin 10 mg/day (CS) to colestipol 10 mg and bezafibrate 400 mg/day (CB) for 2 months in 33 patients with serum total cholesterol > 6.5 mmol/l and triglyceride < 4.5 mmol/l who had undergone CABG for severe coronary artery disease. In the CS group, total cholesterol decreased by 29% and low-density lipoprotein (LDL) cholesterol by 42%; similarly, CB reduced total cholesterol by 17%, LDL cholesterol by 23%, triglyceride by 19%, and increased high-density lipoprotein (HDL) cholesterol by 14%. Lipoprotein (a) and hemostatic factors were unaffected by either therapy in this study. Both combination therapies were well tolerated with no significant clinical or biochemical side effects. We conclude that low-dose combinations of colestipol and simvastatin or colestipol and bezafibrate are effective and well tolerated in the management of moderate hyperlipidemia in patients who had undergone CABG.