Background: This study was designed to compare the in-hospital clinical outcomes and 9-month follow-up of percutanous coronary intervention (PCI) in patients with and without history of coronary artery bypass grafting (CABG).Materials and Methods: 1979 patients who had undergone coronary angioplasty with 9-month follow-up were enrolled into this study. Patients were divided into two groups, with a history of CABG (54 patients) and no history of CABG (1929 patients). Baseline, clinical, and technical characteristics, and short- and long-term outcomes of PCI were compared between groups. Results: Patients with a history of CABG had lower ejection fraction (p=0.001). These patients were older (p=0.05) and had higher frequency of prior PCI (p=0.007), positive family history of coronary artery disease (p=0.05), and multivessel disease (p<0.001). Moreover, the percentage of diabetics and men was higher in this group (p=0.02 and p=0.04, respectively). The lesions in patients with history of CABG were more type B2/C (p=0.01). In this group, PCI had been done more on left circumflex territory (p=0.001). However, procedural and clinical success were not significantly different in patients with history of CABG vs. those without prior CABG (94.4% versus 97%, p=0.7 and 92.6% versus 96.1%, p=0.16), respectively. In follow-up, no difference was noted in target vessel revascularization (TVR) and major adverse cardiac events (MACE) in patients with and without history of CABG (4.2% vs. 3.3%, p=0.67 and 4.5% versus 4.7%, p=0.999). Multivariate analysis also did not show prior CABG to be associated with increased TVR (p=0.98, OR=0.99; 95% CI=0.21-4.70).The predictors of TYR, however were PCI on left anterior descending artery (p=0.03, OR=2.06, 95% CI=1.06-3.99) and previous PCI (p<0.001, OR=5.78, 95% CI=2.92-11.44).Conclusions and Recommendations: PCI outcomes are similar in patients with and without history of CABG. However, the outcomes should be studied more precisely in larger patient populations in prospective studies.