Background and Objectives Intravascular ultrasound (IVUS) is helpful during percutaneous coronary intervention (PCI), because it can be used to confirm good apposition or optimal expansion of stents. In this study, we compared angiographic result as well as clinical outcomes between two different strategies of IVUS-guidance, the selective vs. the routine. Subjects and Methods The study population consisted of 279 patients undergoing electric and emergency intracoronary implatation of TAXUS stent from August 2003 through September 2006. For this study, we divided physicians into two groups; doctors to perform PCI under 'routine' IVUS-guidance vs. PCI under 'selective' IVUS-guidance. Among a total of 279 patients (384 lesions) who underwent PCI with TAXUS stent, 87 patients underwent the procedure under the strategy of 'routine' IVUS-guidance, whereas 192 patients under 'selective' IVUS-guidance. Results The baseline clinical features of the patients are similar between the two groups. The actual rate of IVUS usage was 89.2% in the routine group and 68.2% in the selective group (p<0.01). A high rate of adjunctive ballooning was determined as a remarkable procedure-related parameter which was comparable between the two groups (72.5% vs. 76.1% in routine vs. selective, p=0.57). The minimal lumen diameter at immediate post-PCI was significantly larger in the routine IVUS group than that in the selective group (2.58 mm vs. 2.48 mm, p=0.03). However, the difference disappeared during the follow-up period (1.98 mm vs. 1.98 mm, p=0.94). Clinical outcomes at 1 year were not different between the two groups. Conclusion PCI under the strategy of 'selective' IVUS-guidance was comparable to PCI under 'routine' IVUS-guidance in terms of angiographic and clinical outcomes in circumstances with frequent use of adjunctive ballooning after stenting.