AIMS: Treatment of patients with cancer presenting with ST-elevation myocardial infarction (STEMI) is complex given the increased risk of both thrombotic and major bleeding complications. METHODS AND RESULTS: A nationally linked cohort of STEMI patients between January 2005 and March 2019 was obtained from the UK Myocardial Infarction National Audit Project and the UK National Hospital Episode Statistics Admitted Patient Care registries. The primary outcomes were major bleeding and re-infarction at 1 year following admission with STEMI. Major bleeding was defined as bleeding events that require hospital admission. Re-infarction was defined as acute MI according to the fourth Universal Definition of Myocardial Infarction. A total of 322 776 STEMI-indexed admissions were identified between January 2005 and March 2019. Of those, 7050 (2.2%) patients were diagnosed with active cancer. Cancer patients were older with more cardiovascular comorbidities. Cancer patients received invasive coronary angiography (62.2% vs. 72.7%, CONCLUSION: Compared with non-cancer patients, cancer patients have a higher risk of major bleeding but not of re-infarction. Mitigating bleeding risk in STEMI patients with cancer is of paramount importance to improve outcomes.