The primary purpose of this study was to examine variations in patient characteristics, outcomes, and treatment practices in acute myocardial infarction (AMI) across 11 states. Data from 11 states were extracted from the Healthcare Cost and Utilization Project State Inpatient Dataset. Patients who had a primary diagnosis of AMI (International Classification of Diseases, Ninth Revision, Clinical Modification, code 410.x1) from 11 states were extracted from the Healthcare Cost and Utilization Project 1999 dataset. Bivariate comparisons were conducted to examine the characteristics, treatment practices, and outcomes of patients who had AMI. Multivariate regression models were used to examine the association between geographic location (and other factors) and the likelihood of in-hospital mortality, undergoing coronary artery bypass grafting (CABG), or percutaneous coronary interventions (PCIs). Results revealed considerable variations across states in practice patterns and treatment outcomes. New York had the highest average length of stay (8.2 days, p <0.01), rate of patients who had AMI being transferred (20.7%, p <0.01), and in-hospital case fatality rate (10.7%, p <0.01) and the lowest rate of alive discharges being routine (65.6%, p <0.01). PCI was performed 2 times as often as CABG for patients who had AMI (23.9% vs 11.3%, p <0.01), with patients who underwent CABG being transferred more often. Multivariate analyses showed that state of residence, age, female gender, transfer status, and number of co-morbidities were predictors of in-hospital mortality and the likelihood of undergoing CABG or PCI. In conclusion, large differences in practice patterns and treatment outcomes exist across states.