There is convincing clinical and experimental evidence to support the notion that lipoprotein(a) [Lp(a)] is atherogenic. Patients undergoing chronic hemodialysis have an increased risk of atherosclerotic cardiovascular complications. In the present study, we investigated the possible relation between the alteration, if any, in serum Lp(a) and coronary artery disease in such patients. The mean serum concentration of Lp(a) tended to be higher in the 64 hemodialysis patients than in the 30 normal controls (15.1 +/- 15.2 vs. 9.7 +/- 10.4 mg/dl). However the difference did not reach statistical significance. The prevalence of levels above 30 mg/dl was 14% (9/64) and 10% (3/10), respectively, and the difference was also not statistically significant. Eleven hemodialysis patients with coronary artery disease had a significantly higher mean serum concentration of Lp(a) than the unaffected 53 (33.7 +/- 18.4 vs. 11.1 +/- 11.2 mg/dl, p < 0.001). Elevated levels were present in 63.6% (7/11) and 3.8% (2/53), respectively (p < 0.01). Other parameters of lipid metabolism were not different between the two groups. We observed statistically significant positive correlations of Lp(a) to total cholesterol, LDL cholesterol and apolipoprotein B in controls, in hemodialysis patients as a whole and in those without coronary artery disease. No such correlations were obtained when hemodialysis patients with coronary artery disease were analysed separately. It is concluded that firstly, high serum levels of Lp(a) in hemodialysis patients are strongly associated with coronary artery disease, as well as in the general population; and secondly, abnormalities in the metabolism of Lp(a) may underlie atherogenesis in these patients, independently of alterations in other lipid constituents.