Diabetic patients with coronary artery disease may benefit from elective coronary artery bypass graft (CABG) surgery. It is unknown whether this merit is transferable to patients with acute myocardial infarction (AMI) undergoing surgery. A total of 1,427 patients underwent CABG within 48 hours of being diagnosed with AMI at the current institution between 2001 and 2019. Of these patients, 206 (14.4%) had insulin-dependent diabetes mellitus (IDDM) and 148 (10.4%) had non-insulin dependent diabetes mellitus (NIDDM). Retrospective data analysis was performed. Patients with NIDDM showed the highest perioperative risk profile, with a EuroScore II of 11.6 (±10.3) compared with 7.8 (±8.0) in non-diabetic patients and 8.4 (±7.8) in patients with IDDM (p<0.001). Sub-analysis demonstrated a higher proportion of non-ST-elevation myocardial infarction patients in the NIDDM cohort compared with the IDDM cohort (70.9% vs 56.8%; p=0.005). Postoperatively, NIDDM patients had more sepsis (p<0.01) and longer ventilation times (p<0.001) compared with non-DM and IDDM patients (p<0.01). Wound healing complications were rare, but almost twice as high in NIDDM patients compared with non-DM and IDDM patients (4.7% vs 0.9% vs 2.4%, respectively). The 30-day mortality was highest in the NIDDM cohort (18.3% vs 11.3% vs 7.8%; p=0.012). Analysis of survival for up to 15 years revealed a significantly reduced survival of diabetic patients compared with non-diabetic patients, with lowest survival rates in NIDDM patients (p<0.001). Non-insulin dependent diabetes mellitus patients undergoing CABG within 48 hours of being diagnosed with AMI are at increased risk of short-term and long-term complications. Therefore, this particular group should undergo a careful evaluation concerning the expected risks and benefits of CABG in this setting.