Abnormal glucose metabolism is frequently observed in patients with acute myocardial infarction but less evidence exists for subjects with suspected coronary artery disease. Thus, the prevalence of abnormal glucose metabolism was investigated in 160 consecutive subjects undergoing elective coronary angiography. We observed 15% with normal glucose tolerance, 30% with impaired glucose tolerance and 55% with diabetes (32% previously known) but only 41% with elevated fasting glycemia. In conclusion, our data highlight the high frequency of disturbed glucose metabolism in patients with suspected coronary artery disease and the importance of the oral glucose tolerance test.