Little is known about the efficacy and medium-term outcomes of primary percutaneous coronary intervention (PCI) in very old patients. We evaluated in-hospital and 6-month outcomes in a retrospective cohort of nonagenarian patients presenting at our hospital with ST-segment elevation myocardial infarction (STEMI) and treated by primary PCI from January 2003 to May 2012. During this period, primary PCI was performed in 1598 consecutive patients; twenty-seven patients (age, 92.5 ± 2.5 years) were enrolled in the study. Four patients (15%) were in advanced Killip class at presentation. STEMI location was anterior in 44%. Patients received aspirin, 300 mg clopidogrel loading dose, and heparin. Abciximab was given to 41% of patients. Coronary angiography showed multivessel disease in 52% of patients. Pain-to-balloon and door-to-balloon times were 375.0 ± 410.2 minutes and 107.3 ± 47.6 minutes, respectively. Intra-aortic balloon pump was implanted in 1 patient. An average of 1.3 ± 0.7 stents (95% bare-metal stents) were implanted per patient. Procedural success rate, defined as Thrombolysis in Myocardial Infarction (TIMI) flow grade ≥ 2 and residual stenosis <20%, was 89%. Hospital mortality was 18.5%. TIMI major bleeding and acute renal failure, defined as an absolute increase of 0.5 mg/dL serum creatinine, occurred in 7% and 22% of patients, respectively. Overall 6-month survival rate was 67%. Our data suggest that primary PCI can be performed in nonagenarian patients with high success rate and with an acceptable bleeding risk, even when aggressive antithrombotic drugs, such as glycoprotein IIb/IIIa inhibitors, are given.