Background: High-pressure post-dilation after bare metal stent implantation has been shown to improve procedural success and late clinical outcomes. However, six-month clinical and angiographic outcomes in patients with high-pressure post-dilatation after sirolimus-eluting stent (SES) implantation have never been investigated. Methods: This was an observational retrospective study including consecutive symptomatic patients (n=442) assigned to the high-pressure post-dilation group (HP group, n=128) and no high-pressure group (NHP group, n=314) after SES implantation. All patients underwent angiographic follow-up at six months. Results: Baseline patient and angiographic lesion characteristics were similar between 2 groups. Six-month follow-up angiography showed significantly lower rates of late loss in the HP group (Table). During the six-month follow-up, 3.9% (n=5) in the HP group needed repeated target lesion revascularization compared with 4.1% (n=13) in the NHP group (p = 0.910). Rates of death and myocardial infarction were similar in the 2 groups during the six months follow-up (Table). Conclusions: Six-month angiographic outcomes showed significantly higher minimal lumen diameter and lower late loss in the HP group with similar major adverse cardiac events between 2 groups