Lp(a) is an LDL-like lipoprotein carrying the apoprotein(a) glycoprotein and has recently been recognized to be an independent risk factor for coronary heart disease. We studied plasma Lp(a) levels in 40 patients undergoing maintenance hemodialysis (24 male, 16 female; aged 16–83 years). Fasting plasma Lp(d) levels were measured by an enzyme-linked immunosorbent assay. The median value of plasma Lp(a) concentrations in hemodialysis patients was significantly higher than that of the normal volunteers (26.0±2.7 vs. 10.8±3.7 mgldL, p<. 05). Lp(a) levels did not correlate with age, duration of hemodialysis, total cholesterol, tri-glyceride, HDL cholesterol, or LDL cholesterol. The 11 patients whose plasma Lp(a) concentrations exceeded 20 mgldL received niceritrol, a prodrug ofnicotinic acid, at a dosage of 500 mg t.i.d. for 4 weeks. The plasma Lp(a) levels were significantly lower after 4 weeks of treatment (38.3±4.2 vs. 31.5±3.2 mgldL, p<. 01).