Background Drug-eluting stent (DES) markedly decreased in-stent restenosis (IRA) compared to bare-metal stent (BMS) and balloon angioplasty. It was demonstrated that there was late improvement in luminal diameter with the use of BMS. But sirolimus-eluting stent failed to show long-term inhibition of neointimal hyperplasia in a porcine model. So the risk of late catch-up phenomenon (later progression of neointimal hyperplasia) cannot be ignored. Methods and results From January 2004 to July 2006, the subjects were selected from the patients performed follow up coronary angiogram (CAG) more than 2 times after coronary stent implantation. Follow up CAG were reviewed and the stents implanted previously at non target lesion were subjected to analyze. Serial quantitative coronary analysis (QCA) was done for the measurement of reference vessel diameter (RVD), in-stent minimal luminal diameter (MLD) and diameter stenosis (DS). Results Total 22 patients were performed follow up CAG more than 2 times and the number of stents implanted at the non-target lesion was 25. (BMS, 20: SES, 12: paclitaxel-eluting stent (PES), 3) Baseline characteristics between the groups were not detected. The table shows the result of serial QCA data of the two groups. Between 1st and 2nd follow up CAG, MLD tended to increase (p=0.079, not significant statistically) in the BMS group but continued to decrease in the DES group (p= 0.024) Conclusion After BMS implantation, it was demonstrated that later neointimal thinning occured due to decreased cellular component associated with apoptosis. This phenomenon seems not to occur after DES implantation and later luminal narrowing could be a problem after DES implantation, which demonstrates the need for more careful follow up.