Sleep disordered breathing has been associated with an increased risk for developing coronary heart disease. Data on the effects of sleep disordered breathing on case fatality and prognosis of a myocardial infarction are sparse. The present study aimed to investigate a possible relationship of snoring and case fatality and mortality after an acute myocardial infarction. DESIGN, SETTINGS, PATIENTS, AND MEASUREMENTS: In this study, we enrolled 1660 first acute myocardial infarction cases and examined the effects of self- or relative-reported heavy snoring on case fatality and prognosis. The average follow-up time was 8 years, SD = 262 days.