Hyperglycaemia in the period following myocardial infarction is associated with increased mortality and there is some evidence that its treatment can improve survival. However, it remains unclear as to what the ideal glucose targets might be. This study examined observational data taken from a previously reported randomised controlled trial of insulin therapy for myocardial infarction (The Hyperglycaemia: Intensive Insulin Infusion In Infarction Study), to determine optimal glucose levels for this period. Capillary glucose readings were recorded at 8 standard time points for 234 subjects in first 24h after myocardial infarction. Survival over 6 months was analysed according to whether 80% of each subject's glucose readings were below specified glucose thresholds (Achievers) or not (Non-Achievers). We found that the glucose threshold at which there was greatest separation in mortality between Achievers and Non-Achievers was at 8mmol/L [144mg/dL] (6 month mortality 1.6% vs. 9.1%, p=0.05). Therefore subjects who maintained the majority of their blood glucose levels below 8mmol/L following myocardial infarction had optimal survival outcomes. We suggest that this might be an appropriate glucose target to aim for in the peri-infarct period.