Patients still present with drug-eluting stent (DES) failure despite an angiographically successful implantation. The aim of the present study was to investigate the relation between the fractional flow reserve (FFR) measured after DES implantation and the clinical outcomes at 1 year. A total of 80 patients (mean age 62 years, 74% men, 99 DESs) underwent coronary pressure measurement at maximum hyperemia after successful DES implantation. The composite of major adverse cardiac events (MACE), including death, myocardial infarction, and ischemia-driven target vessel revascularization was evaluated at 1 year. The patients were divided into 2 groups (low-FFR group, FFR ≤0.90 and high-FFR group, FFR >0.90) according to the median FFR. The mean poststent percent diameter stenosis was 11 ± 5% in the low-FFR group and 12 ± 3% in the high-FFR group (p = 0.31). Left anterior descending coronary artery lesions were more frequent in the low-FFR group than in the high-FFR group (82% vs 55%, p = 0.02). The mean stent length was greater in the low-FFR group than in the high-FFR group (38 ± 18 vs 28 ± 13 mm, p = 0.01). Six cases (7.5%) of MACE occurred during the 1-year follow-up. The rate of MACE was 12.5% in the low-FFR group and 2.5% in the high-FFR group (p <0.01). Receiver operating characteristic curves revealed 0.90 as the best cutoff of FFR after DES implantation for the prediction of 1-year MACE. In conclusion, a poststent FFR of ≤0.90 correlated with a greater adverse event rate at 1 year.