Low high density lipoprotein (HDL) cholesterol, elevated triglycerides, or a combination of both, carries an increased risk of coronary heart disease (CHD). The benefit of therapy that increases serum HDL cholesterol concentrations and lowers triglyceride concentrations on the reduced incidence of myocardial infarctions and mortality has not been unequivocally demonstrated in healthy persons or patients with CHD. The Bezafibrate Infarction Prevention (BIP) study randomized men and women, with CHD and with total serum cholesterol 180 - 250 mg. dl-1, low density lipoprotein (LDL) cholesterol < or = 180 mg. dl-1 (< or = 160 mg. dl-1 below age 50 years), HDL cholesterol < or = 45mg. dl-1 and triglycerides < or = 300 mg. dl-1, to bezafibrate retard (400 mg once daily) or placebo. In addition to its effect on the lipids, this drug significantly lower plasma fibrinogen. The demographic, clinical and biochemical characteristics and existing cardiovascular therapy at baseline of 3122 patients randomized onto the study are presented here. A comparison is made with other on-going or recently published secondary prevention studies of lipid modification in CHD patients.