Purpose: Hyperglycemia in patients with ST-segment elevation myocardial infarction (STEMI) has been associated with adverse outcome. We tried to show whether less stringent control of hyperglycemia on the first day of admission would improve outcome. Methods: We enrolled 54 consecutive patients with acute STEMI who had admission blood glucose ≥ 200 mg/dL, in the period from June 2008 to December 2009. Patients were randomized either to intravenous insulin infusion for the first 24 hours with a target blood glucose 140-180 mg/dL then conventional control till hospital discharge (group A) or conventional glycemic control from the start (group B). Patients in group A had their blood glucose measured every hour with titration of insulin infusion. Streptokinase was given within 6 hours from the onset of chest pain. No primary percutaneous coronary interventions (PCI) were done and in hospital PCI were done when indicated. Echocardiography was done before patient’s hospital discharge. Patients were followed up at 6 and 12 months for the occurrence of major adverse cardiac events. Follow up was possible in 47 patients (87%). Results: There was no difference between the 2 groups regarding age, gender, major risk factors, location of infarction, onset of thrombolysis or PCI done. Patients in the intervention arm had lower mean blood glucose in the first 24 hours post admission (151.00 ± 21.52 mg/dL versus 252.66 ± 65.51 mg/dL, p=0.0001). Patients in group A were more likely to have successful thrombolysis (p value = 0.0001), as manifested by more ST segment resolution in ECG after 90 minutes. Also there was a trend towards improvement of sum of ST segment elevation at 90 minutes in group A (p value = 0.05). Patients in group A had less early post MI angina (p = 0.01). No difference between both groups regarding the occurrence of in hospital significant arrhythmias (p=0.2), need for intravenous inotropes (p=1.0) or mechanical ventilation (p=1.0). Also there was no difference as regard in hospital mortality (p=1.0). At 6 months patients in group A had lower rates of recurrent acute coronary syndromes (0% versus 34.6%, p=0.002), hospitalization (0% versus 26.9%, p=0.008), a trend towards lower rate of cardiac mortality (0% versus 15.4%, p=0.05), however there was no difference regarding revascularization (0% versus 7.7%, p=0.15). This effect was still present after 1 year. Multivariate regression analysis was done including admission blood glucose, pre discharge ejection fraction and mean blood glucose in the first 24 hours. The accuracy of the model was 70.8%. There was a trend for high mean blood glucose (OR 1.04, 95% 1.0-1.08, p=0.08) to be an independent predictor for adverse events at 6 months. Conclusion: Less stringent control of hyperglycaemia in patients with acute STEMI, especially the first 24 hours post admission has a favorable effect at 6 months and this effect is still present after 1 year.