Our study provides a comprehensive assessment of the common genetic variation in the CRP gene with plasma CRP levels and risk of incident CHD among two independent populations. Among predominantly Caucasian men and women, CRP genotypes and haplotypes were consistently and significantly associated with plasma CRP levels. However, the relationship between genotype and CRP levels did not translate largely to an associated change in CHD risk, and Haplotype 4 in particular may be important in predicting other clinical events. These data suggest that the underlying inflammatory processes which predict coronary events cannot be captured solely by variation in the CRP gene, and other regulatory genes should be examined.