Background: Patients with chronic total occlusive (CTO) have higher prevalence of diabetes and chronic renal insufficiency (CRI) and further, CTO intervention is definitely higher chance to use larger amount of contrast media due to longer procedure time. Thus, CTO intervention objectively can be more frequently associated acute exacerbation of CRI or new onset acute renal insufficiency. There have been limited data regarding the impact of chronic renal insufficiency on major angiographic and clinical outcomes following percutaneous coronary intervention (PCI) with drug-eluting stents (DES) for CTO lesions. Methods: A total 234 consecutive patients with CTO lesion were underwent PCI with DESs between 2004 and 2010. We compared clinical outcomes of 22 patients with CRI with 212 patients without CRI for at least up to 6 months. Further, we investigated whether there are differences between CTO patients with CRI and non-CTO patients with CRI. All CRI patients were managed with enough prehydration and N-acetylcysteine administration. Results: There were no significant differences between the two groups. At 6 months, major clinical outcomes including cardiac mortality and Q-wave myocardial infarction (MI) were higher in the CRI group. Further, there was a trend toward higher incidence of target lesion revascularization (TLR)-major adverse cardiac events (MACES) in the CRI group (Table). Conclusions: Patients with CTO lesion and combined CRI at baseline showed worse mid-term clinical outcomes as compared with those without CRI following successful CTO PCI with DESs. Updated data will be presented at the time of presention.