Introduction : Serial IVUS studies have shown that DES reduce restenosis by inhibiting neointimal hyperplasia(NIH). However, it remains unknown the effect of overlapping DESs (potentially doubling the local drug dose and different pharmacologic mechanism of sirolimus(S) and paclitaxel(P)) on NIH and whether it would result dose-related side effects. So we assessed the hypothesis that PCI with overlapping with different DES showed similar effect of suppression on NIH and side effects of DES compared with overlapping with same DES. Method : Consecutive 46 patients, from June 2003 to August 2004, were performed PCI with overlapping same or different DES for a diffuse long lesion. Angiographic and IVUS study were performed in all patients before and after PCI. Results : In all 46 patients, 48 lesions were treated with overlapping DES. Nine month-angiographic and IVUS were performed in 40 patient(42 overlapping DES). In 42 overlapping DES, 13 were overlapping of S-P stents, 13 were S-S stents and 16 were P-P stents. On follow-up IVUS, there was no stent thrombosis. However 1 late stent malapposition was observed at distal single stent area. All restenosis were noted proximal or distal single stent area(2 proximal edge of proximal stent, 4 distal stent). In most cases, maximum NIH was noted at single stent area except 1 case(overlapping with P-P stents). In 13 patient who underwent PCI with S-P stents, NIH of overlapping area similar compared to proximal or distal single stent area. Conclusions : In conclusion, compared with overlapping with same DES, PCI with overlapping with different DES showed similar effect on suppression of NIH and did not increase risk of side effect of DES.