Background Regular physical activity has been shown to improve outcome of acute myocardial infarction (AMI) in the elderly population. The aim of this study was to evaluate whether the positive role of an active lifestyle on cardiac prognosis extends to elderly patients with AMI who undergo primary percutaneous transluminal coronary angioplasty (PTCA). Methods We prospectively studied 180 patients with AMI aged ≥70 years and treated with primary PTCA. In all patients, physical activity levels before AMI were quantified by a score derived from the Physical Activity Scale for the Elderly (PASE). Cardiac deaths and nonfatal cardiac events were evaluated within 30 days and 1-year from primary PTCA. Results A high PASE score was significantly associated with a strong reduction of 30-day cardiac deaths (from 23.1% to 4%; P for trend = .021) and overall nonfatal events (from 21.1% to 10%; P for trend = .01). Accordingly, at 1 year of follow-up, the incidence of cardiac mortality and nonfatal events significantly decreased with increasing PASE score (from 28.8% to 8% and from 55.7% to 14.5%, respectively). Logistic regression analysis indicated that physical activity before AMI was an independent predictor of increased survival in those patients that showed the highest PASE scores. In addition, at 6 months of follow-up, although low ejection fraction and recurrent angina strongly predicted 1-year mortality, high PASE scores still predicted a better outcome. Conclusions Our data indicate that an active lifestyle may favorably affect early and late outcomes of primary PTCA in the elderly population.