Inflammation is thought to play a central role in the aetiology and outcome of atherosclerosis. C-reactive protein (CRP) is a prominent product of the inflammatory response syndrome and a marker of overall and cardiovascular death in the general population and in dialysis patients. CRP is 5- to 10-fold higher in haemodialysis patients than in healthy controls and clearly is multifactorial in origin. A number of endogenous factors have been identified in vitro [angiotensin II, lipopolysacharide, modified low-density lipoprotein (LDL), advanced glycation end-products, homocysteine, viral infections] which all are able to trigger a nuclear factor (NF)-kappaB-mediated inflammatory, interleukin-6-driven, response via the generation of oxygen free radicals (oxidative stress). In addition, exogenous factors (dialysate endotoxin, vascular access, cuprophane dialyser material) have been identified in clinical studies which are also responsible, at least in part, for high serum CRP levels. Some of these factors function by themselves as non-traditional cardiovascular risk factors. Whether CRP is simply a marker of cardiovascular disease and mortality or whether it is in the causal pathway of the disease remains an open question. Recent data are in favour of a direct involvement in the pathogenesis of disease, since binding of CRP to degraded LDL enhances complement activation and induces the expression of tissue factor.