Kidney stones are a risk factor for chronic kidney disease (CKD), which, in turn, is a risk factor for myocardial infarction (MI). The objective of this study was to determine whether kidney stones associate with an increased risk for MI. We matched 4564 stone formers (1984 through 2003) on age and gender with 10,860 control subjects among residents in Olmsted County, Minnesota. We identified incident MI by diagnostic codes and validated events by chart review through 2006. We used diagnostic codes to determine incidence of kidney stones and presence of comorbidities (CKD, hypertension, diabetes, obesity, dyslipidemia, gout, alcohol dependence, and tobacco use). During a mean of 9 years of follow-up, stone formers had a 38% (95% confidence interval 7 to 77%) increased risk for MI, which remained at 31% (95% confidence interval 2% to 69%) after adjustment for CKD and other comorbidities. In conclusion, kidney stone formers are at increased risk for MI, and this risk is independent of CKD and other risk factors.