To test the hypothesis that feelings of vital exhaustion precede the onset of myocardial infarction, and to develop a short questionnaire to assess these feelings, a prospective study was done among 3877 males, aged 39-65 years. During a 4.2-year follow-up period, 59 fatal or non-fatal infarctions occurred. The mean score of future coronary causes as determined by a questionnaire assessing feelings of vital exhaustion was significantly higher than the mean score of a control group matched for age, blood pressure, cholesterol and smoking. Given the validity of the model, it was possible to reduce markedly the size of the questionnaire.