Abstract Aims Glucose lowering (GL) therapy in patients with diabetes mellitus (DM) and coronary artery disease (CAD) is prognostically important. This report from the Euro Heart Survey on Diabetes and the Heart describes present practice in relation to 1 year prognosis. Methods and results The survey enrolled 4676 patients with CAD from 110 centres out of whom 1425 had known and 452 newly detected DM. The impact of different GL modalities on cardiovascular events (CVE: death, myocardial infarction, or stroke) was followed. Insulin treated patients with known DM (n = 378) had an adjusted 1 year hazard ratio (HR) for mortality of 2.23 (95% CI 1.24–4.03; P = 0.006) and for CVE of 1.27 (95% CI 0.85–1.87; P = 0.230) compared with those on oral GL drugs (n = 675). Of patients with newly detected DM 77 (17%) were started on GL drugs. None of them died compared with 25 (P = 0.002) among those without such treatment and their 1 year CVE HR was 0.22 (95% CI 0.05–0.97; P = 0.041) compared with untreated subjects. Conclusion Insulin therapy may relate to a more serious prognosis in CAD-patients with DM. There was a pronounced decrease in cardiovascular events in patients with newly detected DM prescribed GL drugs compared with those not receiving such treatment.