This New Zealand based, retrospective analysis (n = 4,408) assessed the predictive value of admission blood glucose (ABG) and ethnicity with respect to the mortality of patients with acute coronary syndromes (ACS). Those patients presenting with acute ST elevation myocardial infarction (STEMI) were more likely to suffer early mortality. Poor patient outcome was also associated with a diagnosis of diabetes mellitus (DM) or elevated ABG (in the absence of DM). Mäori were more likely than European to have diabetes (33% vs 17.5%, p < 0.001). Those patients who made up the highest glucose category were older, more likely to be Mäori, had a higher prevalence of diabetes and longer hospital stays than those patients with lower blood glucose. Mortality risk factors included gender, age, ethnicity, diabetes, glucose and STEMI. The risk of mortality increased by 4.3% with each mmol/l increase in glucose. Following adjustments for age and gender, Mäori ACS patients had a much higher mortality than Europeans (RR 2.12; p < 0.00001), regardless of ACS type, with raised ABG being an indicator of this increased risk.