Data on the prevalence of infections in patients who underwent percutaneous coronary intervention (PCI) and their impact on outcomes are scarce. In this study, a total of 644 patients ≥80 years of age who underwent PCI were stratified according to the presence/absence of infections requiring antibiotic therapy. The primary end point was major adverse cardiovascular events (MACE) after discharge, a composite of all-cause mortality, nonfatal myocardial infarction, and rehospitalization for heart failure. Median follow-up was 1.2 (interquartile range 0.1 to 3.4) years. Of the 644 patients, 186 (28.9%) had infections during index hospitalization, with 84 (13%) and 59 (9.2%) patients having pneumonia and urinary tract infections, respectively. Patients with infections were older, more often women, and had an increased prevalence of atrial fibrillation and congestive heart failure. Infections prolonged hospital stay (10 [7 to 16] vs 5 [3 to 7] days, p <0.001), but were not related to rates of MACE (20% vs 19%, adjusted hazard ratio [HR] 1.41, 95% confidence intervals 0.84 to 2.38, p = 0.20). Pneumonia was significantly associated with increased rates of MACE (27% vs 18%, adjusted HR 2.19, 95% confidence intervals 1.23 to 3.91, p = 0.008) and rehospitalization for heart failure (17% vs 10%, adjusted HR 2.66 (1.25 to 5.63, p = 0.01), whereas urinary tract infections were not. In conclusion, concomitant infections are frequent in patients ≥80 years of age who underwent PCI, and associated with an increased risk of adverse events when affecting the respiratory system.