BACKGROUND Chronic renal failure increases the risk of atherosclerosis. The clearance of low-density lipoprotein (LDL), a major risk factor for atherosclerosis, has been reported as being disturbed in dialysis patients. We studied LDL metabolism in non-dialyzed patients with chronic kidney disease (CKD). METHODS LDL clearance was studied with a radiotracer method in 57 CKD patients and 10 healthy controls. RESULTS In the CKD patients, the fractional catabolic rate of LDL apo B (LDL FCR), an indicator of LDL clearance from plasma, ranged from 0.13 to 0.56 pools/day with a mean value of 0.34 pools/day being comparable to that of the control subjects. In the renal patients, LDL FCR correlated significantly with estimated glomerular filtration rate (eGFR) (r = 0.340, P = 0.010) and this association remained significant after the adjustment with age, body mass index, gender, presence of diabetes and LDL cholesterol concentration (P = 0.004). In CKD patients with eGFR <15 mL/min/1.73 m(2) the mean LDL FCR was significantly reduced when compared to that of CKD patients with eGFR >30 mL/min/1.73 m(2) (P = 0.005). LDL apo B production rate was not associated with renal function or different between renal patients and control subjects. CONCLUSIONS The clearance of LDL seems to be related to the severity of renal impairment, but a remarkable reduction in LDL catabolism can be observed only in patients with advanced renal failure.