Background There is less investigation on the impact of admission diabetic status (newly diagnosed, dietary control,oral medication, insulin injection) on survival among patients following an acute myocardial infarction, with little being known about whether the impact varies with age, gender and race.Methods From the Myocardial Infarction National Audit Project (MINAP), including all 228 hospitals in England and Wales, we identified 83,735 patients first admitted in the MINAP in 2004-5 who had a discharge diagnosis of STEMI or NSTEMI.We employed a multivariate Cox regression model to examine l-year follow-up mortality in relation to baseline admission diabetic status.Results 15,314 patients (18.3%) were diabetic; 7.8% were newly diagnosed, 20.5% dietary control, 44.9% oral medications and 26.9% insulin injection.Compared to non-diabetics, multiple adjusted hazard ratios (HR) for 1-year mortality among patients with newly diagnosed, dietary controlled, orally medicated, and insulin injected diabetes were 1.36 (1.20-1.53), 1.05 (0.97-1.13), 1.20 (1.14-1.26) and 1.45 (1.36-1.54).The impacts were similar between patientswith STEMI and NSTEMI.They increased with younger age; multiple-adjusted HRs at age of<65 years in the four diabetic statuses were 1.77 (1.11-2.82), 1.08 (0.72-1.62), 1.70 (1.36-2.12) and 1.72 (1.38-2.15), at age of 65-79 years 1.15 (0.88-1.49), 0.98 (0.84-1.15), 1.14 (1.03-1.27) and 1.24 (1.10-1.40), and at age of≥3d80 years 1.54 (1.23-1.92), 0.91 (0.79-1.05), 1.05 (0.95-1.16) and 1.03 (0.89-1.19) respectively.There were no gender differences in the impact (e.g.in all the diabetic statuses combined, multiple adjusted HR was 1.22 (1.16-1.28) in men vs 1.23 (1.16-1.30) in women.Compared to Caucasians, South Asian patients seemed to have a higher impact (in all diabetic statuses, 1.48, 1.17-1.86 vs 1.23, 1.1 8-1.27), mainly from insulin injected diabetes (1.83, 1.37-2.45 vs 1.44, 1.35-1.53) and newly diagnosed diabetes (4.03, 2.07-7.88 vs 1.33, 1.17-1.51).Conclusions Among patients experiencing AMI, 1-year mortality was increased with admission diabetic statuses including newly diagnosed, orally medicated and insulin injected, but not with dietary controlled diabetes.Early detection of diabetes and better control of hyperglycemia in younger age patients and south Asians are urged to improve survivals.