Background Increased carotid intima-media thickness (IMT) is known to be associated with adverse cardiovascular events in patients with cardiovascular risk factors or established atherosclerosis. However, the prognostic importance of carotid IMT is uncertain in patients underwent percutaneous coronary intervention (PCI). We sought to evaluate the association of carotid IMT with major adverse cardiovascular events (MACE) including restenosis in patients underwent PCI. Methods A total of 308 consecutive patients underwent PCI were enrolled to measure carotid IMT. Base on the mean values, subjects were divided into greater (n=156, 1.003짹0.14 ���) and lesser IMT (n=152, 0.748짹0.07 ���) groups and followed up for at least 1 year (3013 months). Results Patients with greater carotid IMT were older (61짹9 vs. 57짹10, P=.001), had a significantly higher body mass index (25.0짹3.0 vs. 23.9짹4.0, P=.017), history of previous myocardial infarction (20% vs. 9%, P=.008), and more multivessel disease than those with lesser carotid IMT (P<.001). Restenosis was more common in patients with greater carotid IMT (34.6% vs. 23.0%, P=0.025). Multivariate Cox regression analyses showed that carotid IMT was independent predictor of restenosis. However other MACE did not show any significant differences according to the groups. Conclusions Carotid IMT is independent predictor of restenosis, but not predict any other MACE in patients underwent PCI.