Diabetes has been shown to be associated with worse survival and repeat revascularization (TVR) after primary angioplasty. Drug-eluting stent (DES) may offer benefits in terms of TVR, that may be counterbalanced by an higher risk of stent thrombosis, especially among STEMI patients. Aim of the current study was to evaluate the impact of diabetes on 5-year outcome in patients undergoing primary angioplasty with glycoprotein IIb-IIIa inhibitors in the era of DES. Our population is represented by STEMI patients undergoing primary angioplasty and stent implantation at a tertiary center with 24-h primary PCI capability within 12 h of symptom onset. All patients received glycoprotein IIb-IIIa inhibitors. No patient was lost to follow up. From 2003 to 2005, 270 STEMI patients were treated with DES (n = 180), or BMS (n = 90). A total of 69 patients had history of diabetes at admission (25.5%). At a follow-up of 1510 +/- 406 days, diabetes was associated with a higher rate of death (29.5 vs. 5.1%, P < 0.0001), reinfarction (24.1 vs. 9.1%, P < 0.0001), TVR (19.1 vs. 13.1%, P = 0.052), IST (17.2 vs. 6.8%, P < 0.001) and MACE (51.9 vs. 25.1%, P < 0.001). These results were confirmed in both patients receiving BMS or DES, except for TVR, where no difference was observed between diabetic and non-diabetic patients. This study shows that among STEMI patients undergoing primary angioplasty with Gp IIb-IIIa inhibitors, diabetes is associated with worse long-term mortality, reinfarction, and IST, even with DES implantation, that, however, were able to equalize the outcome in terms of TVR as compared to non diabetic patients.