During the preparation of a prospective study of exhaustion as a precursor of myocardial infarction (MI), the authors found that many coronary patients said that they had been burned out at some time in their lives. Therefore, the question, "Have you ever been burned out?" was included in the study. The cohort was formed by 3,877 men, aged 39 to 65, and was followed up on for 4.2 years. Among the men who were free of coronary heart disease (CHD) at screening, 59 subjects experienced a fatal or nonfatal myocardial infarction during follow-up. Those who endorsed the above question when they entered the study were found to be at increased risk for myocardial infarction when the authors controlled for age, blood pressure, smoking, and cholesterol; RR (relative risk) = 2.13; p less than .01. About one third of those who were exhausted before myocardial infarction had been burned out at some time in their lives, chi 2 = 7.09, p less than .01. The data indicate that a state of exhaustion before myocardial infarction is often a reactivation of earlier periods of breakdown in adaptation to stress.