Coronary artery disease is a common and serious condition in diabetes and the prognosis of the diabetic without a history of cardiovascular disease is either the same or nearly as serious as that of a non-diabetic patient with a history of coronary disease. This is particularly true in women. The prognosis is even worse in the presence of silent myocardial ischaemia. Conversely, anti-ischaemic and anti-thrombotic therapy and myocardial revascularisation of most severely affected patients are effective. This justifies the recent recommendations (as those of the working group of the French Society of Cardiology and the ALFEDIAM) for the diagnosis of coronary artery disease in diabetes, even in asymptomatic patients. This is a two stage process: --First, the identification of patients who should be screened for ischaemia, diabetics with a priori an intermediate or high risk of the presence of CAD, with respect to the presence of markers easily identified on initial examination, like the presence of clinical macroangiopathy (femoral, carotid), of renal disease or ECG changes or the presence of several classical risk factors; --The second stage is the demonstration of myocardial ischaemia in patients identified to be at risk. This article reviews the advantages and limits of the tests available: ECG stress test, myocardial perfusion imaging on effort or under dipyridamole, stress echocardiography. Coronary angiography in asymptomatic patients is only recommended in the presence of significant ischaemia or with a poor prognosis (affecting over 20% of the myocardium or several myocardial territories). This should precede a myocardial revascularisation procedure. The prescription of coronary angiography may be more direct in some symptomatic patients.