Background. Older patients are less likely to receive percutaneous coronary intervention (PCI) for acute myocardial infarction (AMI) compared to younger patients. We investigated the prognostic impact of PCI in a large population of patients hospitalized with AMI in the period 2003–2018 by using the administrative Lombardy Health Database (Italy). Methods. We considered all patients aged ≥75 years hospitalized with AMI (either STEMI or NSTEMI) from 2003 to 2018 in Lombardy. Patients were grouped according to whether they were treated or not with PCI during the index hospitalization. The primary outcome was in-hospital mortality. The secondary endpoints were 1-year mortality and 1-year re-hospitalization for acute heart failure (AHF) or AMI. Results. 116,063 patients aged ≥75 years (mean age 83 ± 6; 48% males; 46% STEMI) were hospitalized with a primary diagnosis of AMI. Thirty-seven percent of them (n = 42,912) underwent PCI. The in-hospital mortality rate was significantly lower in PCI-treated patients (6% vs. 15%; p < 0.0001). One-year mortality and 1-year re-hospitalization for AHF/AMI were less frequent in PCI-treated patients (16% vs. 41% and 15% vs. 21%, respectively; p < 0.0001). The adjusted risks of the study endpoints were lower in PCI-treated patients: OR 0.37 (95% CI 0.36–0.39) for in-hospital mortality; HR 0.37 (95% CI 0.36–0.38) for 1-year mortality; HR 0.74 (95% CI 0.71–0.77) for 1-year re-hospitalization for AHF/AMI. Similar results were found in STEMI and NSTEMI patients considered separately. Conclusions. Our real-world data showed that in patients with AMI ≥ 75 years of age, PCI use is associated with lower in-hospital and 1-year mortality.