Lipids, lipoproteins, apolipoproteins (apo) and apo E polymorphism were determined in 101 men with chronic renal failure (CRF) were were on hemodialysis and 101 healthy controls matched for age and sex. Patients with CRF on hemodialysis had significantly higher levels of serum triglycerides, very-low-density lipoprotein (VLDL) cholesterol, intermediate-density lipoproteins (IDL), and lower levels of low- and high-density lipoproteins (LDL and HDL, respectively) than controls. Regarding apolipoproteins, serum apo B concentrations were decreased. Apo C-III concentrations in sera and in VLDL and HDL fractions were significantly increased in 35 hemodialysis patients compared with 32 controls. Seventy-eight of the 101 CRF patients had normal serum cholesterol and triglycerides (less than 5.2 mmol/liter and less than 2.3 mmol/liter, respectively). However, this subgroup also showed a significant increase in VLDL-triglycerides and serum apo E concentration in addition to changes observed in the group as a whole. Apo E polymorphism in our study population did not differ from that reported for other European populations. According to the different apo E phenotypes, lipids and lipoprotein composition showed no significant differences in controls or patients. We conclude that accumulation of triglyceride-rich lipoproteins in patients with CRF on hemodialysis may thus be at least in part related to the enrichment of apo C-III in VLDL and HDL fractions. Lipoprotein profile in hemodialysis patients, including those with normal serum cholesterol and triglyceride levels, is consistent with high cardiovascular risk.