Background: Recently retrograde wire approach was developed as a new technique in the chronic total occlusion (CTO) intervention. Therefore we sought to investigate the impact of retrograde approach in CTO intervention. Methods: Total 184 patients(143 mal, mean age 57 yrs) with CTO patients were selected in our hospital between January 2004 and July 2008 and underwent percutaneous coronary intervention (PCI) procedures before or after the introduction of PCI combined with retrograde approach. Study patients were divided into two groups: Conventional CTO PCI group (n=129, from Jan. 2003 to Feb. 2007) and Retrograde approach period group (n=55, from Feb. 2007 to Jul. 2008). We compared the success rate between 2 groups. Results:Treated vessels included left anterior descending in 96(52%), right coronary artery in 64(34%) and left circumflex in 24(13%) patients. The ratio of risk factor, left ventricular ejection fraction, and CTO lesion site and collateral grade did not show any statistical difference between two groups. The success rate was relatively higher in the retrograde period group compared to conventional PCI period group(85.2% vs. 75.2%, p=0.13). Conclusions: Although there was no statistical difference, there is a trend to improve the success rate of PCI intervention in CTO patients. Therefore, retrograde approach in CTO intervention could give increase success rate in the future.