BACKGROUND The current techniques for percutaneous coronary interventions (PCI) remain limited by restenosis. Recent studies have provided evidence of inflammation playing a role in the pathogenesis of cardiovascular disease. METHODS Whether inflammatory markers are predictors of subsequent restenosis were prospectively tested in 272 consecutive patients with angiographically proven coronary artery disease. Patients having undergone PCI at Chonnam National University Hospital, between Sept. 1999 and Mar. 2001, were divided into two groups according to the occurrence of restenosis on a follow-up coronary angiogram: Group I were patients with restenosis (n = 99, 59.5 +/- 10.8 years, M:F = 77:22) and Group II were those without restenosis (n = 173, 58.8 +/- 10.2 years, M:F = 131:42). The IgG seropositivity, cytomegalovirus (CMV) titers, C. pneumoniae. H. pylori and levels of C-reactive protein (CRP) were compared between the two groups. RESULTS There were no statistical differences in the seropositivity of the CMV IgG C. pneumoniae IgG and H. pylori IgG between the two groups (Groups I vs. II: 100 vs. 100%, 24.7 vs. 25.7% and 62.2 vs. 63.7%, respectively). Of the angiographic parameters, a low Thrombolysis in Myocardial Infarction (TIMI) flow (TIMI 0 or 1) was more common in Group I than Group II (p = 0.038). The patients with an elevated CRP (> 0.5 mg/dL) were more common in Group I than Group II (57.6 vs. 36.4%, p = 0.001), with the CRP values being higher in Group I than Group II (3.3 +/- 5.8 vs. 1.3 +/- 2.6 mg/dL, p = 0.001). According to a multiple logistic regression analysis, the CRP was the only predictor of restenosis, with an odds ratio of 2.1169 (95% C.I. 1.2062-3.7154, p = 0.009). CONCLUSION The CRP value is the most important predictor of restenosis after PCI.