Complex high-risk indicated percutaneous coronary intervention (CHIP-PCI) is a poorly defined concept, which has not been validated in an older population before. This study aimed to evaluate the predictive value of the CHIP-PCI score in a large cohort of elderly patients and to identify potential further risk factors. This is a pooled analysis of 3 registries that included patients aged ≥75 years who underwent percutaneous coronary intervention from 2012 to 2019: the multicenter prospective EPIC05-Sierra 75 study, the multicenter retrospective PACO-PCI (EPIC-15) registry, and the single-center, prospective Elderly-HCD registry. A total of 2,725 patients with a mean age of 81 ± 4 years were included in the study; 269 patients (10%) met the primary end point of 1-year major adverse cardiac and cerebrovascular events (MACCEs), and 51 patients (2%) had in-hospital MACCEs. Of the 12 investigated original CHIP-PCI score variables, 5 were independent predictors: previous myocardial infarction, left ventricular ejection fraction <30%, chronic kidney disease, left main coronary artery percutaneous coronary intervention, and nonradial access. Furthermore, diabetes mellitus, anemia, and severe calcification showed to be significant predictors of MACCEs. The additional variables improved the discriminatory value of the CHIP-PCI score for 1-year MACCEs (modified CHIP-PCI score: area under the curve [AUC] 0.647 vs original CHIP-PCI score: AUC 0.598, p = 0.02) and in-hospital MACCEs (AUC 0.729 vs 0.657, p = 0.003, respectively). In conclusion, the CHIP-PCI score retains its prognostic value in older patients for in-hospital MACCEs; however, it is of limited value at 1-year follow-up. The modified CHIP-PCI score, including the 5 patient-related and 3 procedure-related factors, significantly improved its discriminatory potential.