To evaluate the usefulness of preoperatie coronary angiography in patients undergoing preoperative investigation because of valvular heart disease, we performed coronary angiography in a consecutive series of 329 patients. The prevalence of significant coronary artery disease was 32%. Asymptomatic coronary artery disease was present in 13%. Angina pectoris proved to be a poor predictor of coronary artery disease in aortic valve disease. In mitral valve disease, however, the specificity was high. A cost-benefit calculation was carried out in order to assess what advantage routine coronary angiography might have. According to this, coronary angiography should be performed in all patients suffering from valvular heart disease with angina pectoris, whereas it can be omitted in younger patients without angina. A cut-off point of 60 years seems appropriate for aortic valve disease and 65 years for mitral valve disease.