Reports from large studies using administrative data sets and event registries have characterized recent temporal trends and treatment patterns for acute myocardial infarction. However, few were population based, and fewer examined differences in patterns of treatment for patients presenting with ST-segment elevation myocardial infarction (STEMI) and non-ST-segment elevation myocardial infarction (NSTEMI). The aim of this study was to examine 22-year trends in the use of 10 medical therapies and procedures by STEMI and NSTEMI classification in 30,986 definite or probable myocardial infarctions in the Atherosclerosis Risk in Communities (ARIC) Community Surveillance Study from 1987 to 2008. Weighted multivariate Poisson regression, controlling for gender, race and center classification, age, and Predicting Risk of Death in Cardiac Disease Tool score, was used to estimate average annual percentage changes in medical therapy use. From 1987 to 2008, 6,106 hospitalized events (19.7%) were classified as STEMIs and 20,302 (65.5%) as NSTEMIs. Among patients with STEMIs, increases were noted in the use of angiotensin-converting enzyme inhibitors (6.4%, 95% confidence interval [CI] 5.7 to 7.2), antiplatelet agents other than aspirin (5.0%, 95% CI 4.0% to 6.0%), lipid-lowering medications (4.5%, 95% CI 3.1% to 5.8%), β blockers (2.7%, 95% CI 2.4% to 3.0%), aspirin (1.2%, 95% CI 1.0% to 1.3%), and heparin (0.8%, 95% CI 0.4% to 1.3%). Among patients with NSTEMIs, the use of angiotensin-converting enzyme inhibitors (5.5%, 95% CI 5.0% to 6.1%), antiplatelet agents other than aspirin (3.7%, 95% CI 2.7% to 4.7%), lipid-lowering medications (3.0%, 95% CI% 1.9 to 4.1%), β blockers (4.2%, 95% CI 3.9% to 4.4%), aspirin (1.9%, 95% CI 1.6% to 2.1%), and heparin (1.7%, 95% CI 1.3% to 2.1%) increased. Among patients with STEMIs, decreases in the use of thrombolytic agents (-7.2%, 95% CI -7.9% to -6.6%) and coronary artery bypass grafting (-2.4%, 95% CI -3.6% to -1.2%) were observed. Similar increases in percutaneous coronary intervention and decreases in the use of thrombolytic agents and coronary artery bypass grafting were noted among all patients. In conclusion, trends of increasing use of evidence-based therapies were found for patients with STEMIs and those with NSTEMIs over the past 22 years.