The Italian network on acute coronary syndromes outcome (IN-ACS Outcome) study is a nationwide observational, multicenter study with the aim to describe clinical epidemiology, management, 30-days and one-year outcomes of ACS in Italy.All consecutive patients admitted for ACS to 38 hospitals, between December 2005 and February 2007, were enrolled in the study. Patient in-hospital details and follow-up data at 30-days and one-year were collected using a web-based CRF and stored in a central database.A total of 6045 patients (age 68 ± 13 years) were enrolled: 2313 patients (38.3%) had ST elevation myocardial infarction (STEMI) and 3732 (61.7%) patients had NSTE-ACS. Primary PCI was performed in 1085 (46.9%) STEMI patients, thrombolysis in 590 (25.5%) patients, whereas 638 (27.6%) patients were not reperfused. Among patients with NSTE-ACS, coronary angiography was performed in 2797 (75%) patients, PCI in 1797 (48.2%) patients and CABG in 213 (5.7%) patients. Thirty-days and one-year mortality rates were 5.8% and 9.8%, in STEMI patients and 3.1% and 8.6%, in NSTE-ACS patients.The IN-ACS Outcome study showed that the management of ACS is still suboptimal. Although 30-days mortality is low, the one-year mortality is still substantial.