In Korea, revascularization techniques for coronary artery disease (CAD), such as Percutaneous Coronary Intervention (PCI), are becoming more common. However, research into blood pressure control targets in these patients is still lacking. The goal of this study was to see if there was a link between baseline blood pressure and all-cause mortality in CAD patients who had PCI. A population-based retrospective cohort research based on the Korean National Health Insurance System's national claims database, which covers the entire Korean population. A total of 38,330 patients having a history of PCI for CAD were enrolled in the study and were tracked for all-cause death. The participants' baseline systolic and diastolic blood pressures (SBP and DBP) were measured, and they were divided into eight SBP and DBP groups. For each group, the hazard ratios (HRs) for all-cause death were calculated. For all-cause mortality, the trend of SBP and DBP in this cohort followed a J-curve relationship, with the nadir points at 119 and 74 mmHg, respectively. High SBP (160 mmHg) and high DBP (90 mmHg) were found to be strongly associated to death in people over 60. Low DBP (below than 70 mmHg) was also linked to death in people over the age of 60. In individuals who underwent PCI, there is a J-curve link between baseline blood pressure and all-cause mortality, and rigorous blood pressure lowering may be advantageous for these patients. Excessive BP lowering, particularly DBP, may, on the other hand, raise the risk of death in the senior population.