The presence of MetS was calculated at baseline using the NCEP-ATP III criteria. The primary outcome was MACCE and its components were secondary outcomes. Unadjusted and adjusted Cox Regression models were used to calculate hazard ratios (HRs) and 95% confidence intervals (CI) of the association between MetS or its components and MACCE and its components. A total of 13,459 ACS patients who underwent PCI (MetS: 7939 and non-MetS: 5520) with a mean age of 62.7 ± 11.0 years (male: 72.5%) were included and median follow-up time was 378 days. Patients with MetS had significantly higher MACCE risk (adjusted HR [aHR] 1.22, 95% CI 1.08-1.39). The only component of MACCE that exhibited a significantly higher incidence in MetS patients was myocardial infarction (aHR 1.43, 95% CI 1.15-1.76). MetS components that were significantly associated with a higher incidence of MACCE were hypertension and impaired fasting glucose. Having three MetS components did not increase MACCE (aHR 1.12, 95% CI 0.96-1.30) while having four (aHR 1.32, 95% CI 1.13-1.55) or five (aHR 1.42, 95% CI 1.15-1.75) MetS components was associated with a higher incidence of MACCE. MetS was associated with a higher risk of MACCE in ACS patients undergoing PCI. Among MACCE components, myocardial infarction was significantly higher in patients with MetS. Impaired fasting glucose and hypertension were associated with a higher risk of MACCE. Identifying these patterns can guide clinicians in choosing appropriate preventive measures.