It has recently been reported that inflammatory markers, such as C-reactive protein (CRP) and interleukin-6 (IL-6), increase in plasma as a response to the stimulus of percutaneous coronary intervention (PCI). The magnitude of this inflammatory response is associated with the risk of restenosis. There is a large inter-individual variation in the inflammatory response to PCI. One factor shown to be of importance is stent implantation but the reasons for the variation are to a large extent unknown. One possible reason could be genetic variation in the regulation of CRP and IL-6 levels. One functional single nucleotide polymorphism (SNP) located at position -286 in the promoter region of the CRP gene associated with plasma CRP levels has recently been described. Another SNP located at -174 in the promoter region of the IL-6 gene has been associated with plasma IL-6 concentration. The hypothesis behind the present study was that the SNPs CRP -286 and IL-6 -174 were associated with the inflammatory response to PCI, including stent implantation. The results did not show any association with plasma levels of CRP and IL-6 measured as area-under-curve up to 72 hours after PCI indicating that genetic variation is unlikely to play a major role for the inflammatory response to PCI.