Background Treatment of bifurcation lesions by PCI remains challengable due to the unfavorable outcomes. If either main (MB) or side branch (SB) have the small diameter, we may expect worse outcomes. Whether there are different outcomes between the patients with small stenting in MB and SB is still known. Methods A total 90 patients with single, small (less than 2.50 mm), denovo coronary artery lesion located either MB or SB were implanted with single DES at the lesion segment. Among them, 6-month angiographic and clinical outcomes of DES implanted in MB (51 lesions) were compared with those of DES in SB (39 lesions). Results The baseline characteristics were similar between two groups except the calcified lesions were more common in MB group (20.4% vs. 5.1%, p=0.038). At 6 months, the incidence of binary restenosis was relatively high as 22.7%. However, there were no differences between two groups in angiographic and clinical outcomes. The survival and freedom from MACEs was similar between two groups (98.0% vs. 97.4%, P=1.000). Conclusion DES implantation in MB or SB in patients with small vessel bifurcation lesions was safe and showed similarly excellent clinical outcomes despite the incidence of binary restenosis remained high. The location of implanted DES don't appear remarkable impact on the mid-term outcomes in this subset of patients.