In order to study the association between vital exhaustion and different manifestations of coronary heart disease, a prospective study was conducted among 3877 males, aged 39-65. This group was studied during a mean period of 4.2 years. Vital exhaustion, a mental state characterized by unusual fatigue, a feeling of being dejected or defeated, and increased irritability, were assessed by means of the Maastricht Questionnaire. Subjects who scored in the upper third were labelled as exhausted and were compared with those who scored in the lower or middle third. The age-adjusted relative risk of angina pectoris at screening that was associated with vital exhaustion was 4.17 (p less than 0.01); that of unstable angina pectoris at screening was 17.21 (p less than 0.001). No association was observed between vital exhaustion and past myocardial infarction, except in the youngest age group (OR = 3.76; p = 0.05). Among the subjects free from coronary heart disease at screening, 54 cases of angina pectoris, 38 cases of non-fatal myocardial infarction, and 21 cases of fatal myocardial infarction were observed during follow-up. The age-adjusted relative risk of angina pectoris at follow-up was found to be 1.86 (p less than 0.03) and that of non-fatal myocardial infarction was found to be 2.28 (p less than 0.001). No association was found between vital exhaustion and fatal events.