Acute organophosphate and carbamate pesticide poisonings result in adverse cardiac outcomes. The cardiac effects of chronic low-level pesticide exposure have not been studied. The authors analyzed self-reported lifetime use of pesticides reported at enrollment (1993-1997) and myocardial infarction mortality through 2006 and self-reported nonfatal myocardial infarction through 2003 among male pesticide applicators in the Agricultural Health Study. Using proportional hazard models, the authors estimated the association between lifetime use of 49 pesticides and fatal and nonfatal myocardial infarction. There were 476 deaths from myocardial infarction among 54,069 men enrolled in the study and 839 nonfatal myocardial infarctions among the 32,024 participants who completed the follow-up interview. Fatal and nonfatal myocardial infarctions were associated with commonly reported risk factors, including age and smoking. There was little evidence of an association between having used pesticides, individually or by class, and myocardial infarction mortality (e.g., insecticide hazard ratio (HR) = 0.91, 95% confidence interval (CI): 0.67, 1.24; herbicide HR = 0.74, 95% CI: 0.49, 1.10) or nonfatal myocardial infarction incidence (e.g., insecticide HR = 0.85, 95% CI: 0.66, 1.09; herbicide HR = 0.91, 95% CI: 0.61, 1.36). There was no evidence of a dose response with any pesticide measure. In a population with low risk for myocardial infarction, the authors observed little evidence of increased risk of myocardial infarction mortality or nonfatal myocardial infarction associated with the occupational use of pesticides.