Author's summary The current study showed that pre-percutaneous coronary intervention (PCI) fractional flow reserve (FFR) was associated with target vessel failure (TVF) after PCI. When the prognostic value of post-PCI FFR was evaluated according to pre-PCI FFR value, the risk of TVF significantly decreased along with the increase of post-PCI FFR in the low pre-PCI FFR group, but not in the high pre-PCI FFR group. Our study results suggest that patient prognosis can be varied according to the level of physiologic indices, both before and after PCI, and the integration of both information can provide better risk stratification after PCI.