To determine possible associations between lipoprotein(a) [Lp(a)] and the severity of coronary artery lesions, we measured lipid, apolipoprotein, and Lp(a) in a large population of Belgian patients (n = 1054) undergoing coronary angiography. In both women and men, univariate analysis demonstrated significant differences in the Lp(a) concentrations according to the severity of the coronary stenosis. However, after adjustment for possible confounding factors, many of these differences were attenuated, indicating that other variables that differentiate patients from control subjects also influence Lp(a) distribution. Differences in lipid, apolipoprotein, and Lp(a) concentrations between male and female patients are discussed.