BACKGROUND: The long-term prognostic impact of post-discharge bleeding in the unique population of patients with acute coronary syndrome (ACS) treated without percutaneous coronary intervention (PCI) remains unexplored. OBJECTIVES: The aim of this study was to assess the association between post-discharge bleeding and subsequent mortality after ACS according to index strategy (PCI or no PCI) and to contrast with the association between post-discharge myocardial infarction (MI) and subsequent mortality. METHODS: In a harmonized dataset of 4 multicenter randomized trials (APPRAISE-2 [Apixaban for Prevention of Acute Ischemic Events-2], PLATO [Study of Platelet Inhibition and Patient Outcomes], TRACER [Thrombin Receptor Antagonist for Clinical Event Reduction in Acute Coronary Syndrome], and TRILOGY ACS [Platelet Inhibition to Clarify the Optimal Strategy to Medically Manage Acute Coronary Syndromes]), the association between post-discharge noncoronary artery bypass graft-related GUSTO (Global Use of Strategies to Open Occluded Coronary Arteries) moderate, severe, or life-threatening bleeding (landmark 7 days post-ACS) and subsequent all-cause mortality was evaluated in a time-updated Cox proportional hazards analysis. Interaction with index treatment strategy was assessed. Results were contrasted with risk for mortality following post-discharge MI. RESULTS: Among 45,011 participants, 1,133 experienced post-discharge bleeding events (2.6 per 100 patient-years), and 2,149 died during follow-up. The risk for mortality was significantly higher <30 days (adjusted hazard ratio: 15.7; 95% confidence interval: 12.3 to 20.0) and 30 days to 12 months (adjusted hazard ratio: 2.7; 95% confidence interval: 2.1 to 3.4) after bleeding, and this association was consistent in participants treated with or without PCI for their index ACS (p for interaction = 0.240). The time-related association between post-discharge bleeding and mortality was similar to the association between MI and subsequent mortality in participants treated with and without PCI (p for interaction = 0.696). CONCLUSIONS: Post-discharge bleeding after ACS is associated with a similar increase in subsequent all-cause mortality in participants treated with or without PCI and has an equivalent prognostic impact as post-discharge MI.