Relatively limited data are available, particularly from the perspective of a multinational registry, about the post-discharge outcomes and management practices of patients with an acute coronary syndrome (ACS). The objectives of this longitudinal study were to examine 6-month outcomes in a large multinational sample of patients hospitalized with an ACS. A total of 5,476 patients with ST-segment elevation acute myocardial infarction (STEAMI), 5,209 patients with non-ST-segment elevation acute myocardial infarction (NSTEAMI), and 6,149 patients with unstable angina pectoris discharged from 90 hospitals in 14 countries comprised the study population. The study sample was recruited from 18 cluster sites in 14 countries that are currently collaborating in the Global Registry of Acute Coronary Events (GRACE) study. The 6-month post-discharge death rates were 4.8% in patients with STEAMI, 6.2% in patients with NSTEAMI, and 3.6% in patients with unstable angina pectoris. Approximately 1 in 5 of each of our comparison groups were rehospitalized for heart disease during the 6-month follow-up, and approximately 15% of each of the respective study cohorts underwent coronary revascularization during follow-up. Demographic and clinical characteristics of post-discharge decedents were identified according to type of ACS. Our results suggest that a considerable proportion of patients who were discharged from the hospital after an ACS, with some differences noted according to type of ACS, remain at increased risk for adverse outcomes during the relatively brief post-discharge period. These data suggest the need for better long-term medical management and more intense follow-up of patients with an ACS to improve their long-term outlook.