Background: Patients suffering post operative myocardial infarction (PMI) have higher mortality and morbidity rates than observed with non-PMI subsets. Little is known about the true incidence of PMI and how PMI differs from non-PMI with regard to clinical presentation, management and outcome. Methods: We examined the incidence and outcomes of patients with PMI in 1212 subjects (≥65 years) undergoing hip fracture surgery from 1988 – 2002 using a population-based retrospective cohort study from the Rochester Epidemiology Project in Olmstead County, Minnesota. PMI was defined on the basis of cardiac biomarker and/or electrocardiographic evidence of definitive MI within 7 days post operatively. Results: PMI occurred in 170 (14.0%) patients yet only 36 (21.2 %) patients had one or more clinical symptoms suggesting coronary ischemia. One or more classic symptoms of myocardial infarction were present in 26 (15.3%) including shortness of breath (SOB) in 18 (10.6%), chest/arm pain in 11 (6.5%), nausea/vomiting in 8 (4.7%) and diaphoresis in 1 (0.6%). Delirium was present in 15 (8.8%) patients. Median hospital length of stay was longer (10.0 vs. 8 days, p<0.01) and the in-hospital mortality rate was significantly higher (14.1% vs. 1.6%, p<0.001) among patients who had PMI within 7 days. Conclusion: The clinical presentation of PMI differs from non-PMI in the elderly undergoing hip fracture surgery. Most patients were asymptomatic or had atypical clinical presentations. We observed a significantly higher rate of hospital mortality among those experiencing a PMI. Further studies are necessary to better understand the presentation, optimal management and prevention of PMI. Table 1. Study Population Table 2. Clinical Presentation and Outcomes in Patients with and without Post Operative MI This research has received full or partial funding support from the American Heart Association, National Center.