Aim: Guideline implementation programs are of paramount importance in optimizing acute ST-elevation myocardial infarction (STEMI) care. Assessment of performance indicators from a local STEMI network will provide knowledge of how to improve the system of care. Methods and Results: Between 2008-2011, 1505 STEMI patients were enrolled. We compared the performance indicators before (n = 869) and after implementation (n = 636) of a local STEMI network. In 2011 (after introduction of STEMI networking) compared to 2008-2010, there were more inter-hospital referrals for STEMI patients (61% vs 56%, p<0.001), more primary percutaneous coronary intervention (PCI) procedures (83% vs 73%, p = 0.005), and more patients reaching door-to-needle time ≤30 minutes (84.5% vs 80.2%, p<0.001). However, numbers of patients who presented very late (>12 hours after symptom onset) were similar (53% vs 51%, NS). Moreover, the numbers of patients with door-to-balloon time ≤90 minutes were similar (49.1% vs 51.3%, NS), and in-hospital mortality rates were similar (8.3% vs 6.9%, NS) in 2011 compared to 2008-2010. Conclusion: After a local network implementation for patients with STEMI, there were significantly more inter-hospital referral cases, primary PCI procedures, and patients with a door-to-needle time ≤30 minutes, compared to the period before implementation of this network. However, numbers of patients who presented very late, the targeted door-to-balloon time and in-hospital mortality rate were similar in both periods. To improve STEMI networking based on recent guidelines, existing pre-hospital and in-hospital protocols should be improved and managed more carefully, and should be accommodated whenever possible.