There is accumulating evidence that inflammation is an important risk factor in cardiovascular disease (CVD). Elevated levels of the inflammatory marker high-sensitivity C-reactive protein (hs-CRP) are associated with increased risk for CVD and diabetes mellitus. Adding hs-CRP to the definition of the metabolic syndrome has been shown to improve the prediction of CVD. Elevated hs-CRP levels may also be predictive of development of the metabolic syndrome. Current definitions of the metabolic syndrome differ, and cardiovascular risk appears to differ according to which component risk factors are present. Further studies are required to identify a widely accepted criterion for the syndrome that will optimally predict the risk of diabetes and CVD. It is possible that such a definition will include a measure of inflammation.