Background Patients from lower socioeconomic status areas have poorer outcomes following acute myocardial infarction (AMI); however, how ethnicity modifies such socioeconomic disparities is unclear. Methods Using the UK Myocardial Ischaemia National Audit Project (MINAP) registry, we divided 370 064 patients with AMI into quintiles based on Index of Multiple Deprivation (IMD) score, comprising seven domains including income, health, employment and education. We compared white and ‘ethnic-minority’ patients, comprising Black, Asian and mixed ethnicity patients (as recorded in MINAP); further analyses compared the constituents of the ethnic-minority group. Logistic regression models examined the role of the IMD, ethnicity and their interaction on the odds of in-hospital mortality. Results More patients from the most deprived quintile (Q5) were from ethnic-minority backgrounds (Q5; 15% vs Q1; 4%). In-hospital mortality (OR 1.10, 95% CI 1.01 to 1.19, p=0.025) and major adverse cardiovascul