Background It is unclear whether edge segments have different responses to paclitaxel eluting stent (PES) and sirolimus eluting stent (SES) implantation in patients with unstable angina. This study aimed to compare the different vascular edge responses in patients with unstable angina and single de novo coronary lesion treated with SES and PES. Methods Two hundred and fifty-five patients with unstable angina and single de novo lesion were randomly assigned to PES and SES groups. Serial volumetric intravascular ultrasound (IVUS) images were taken immediately after stenting and at an eight-month follow-up. Five-mm edge segments proximal and distal to the stents were analyzed. Results Baseline characteristics were comparable between the two groups. At proximal-edge segment, the vessel area decreased and the plaque area increased significantly in the PES group as compared with the SES group. A significant net loss of lumen area was found in the PES group (from (11.10±3.12) mm2 at baseline to (9.92+3.59) mm2 at the follow-up, P