OBJECTIVES: To describe UK patients with acute coronary syndrome (ACS) who receive percutaneous coronary intervention (PCI) or are medically managed only (MM) and evaluate factors affecting approaches to treatment. METHODS: Patients registered with a general practice participating in the Clinical Practice Research Datalink (CPRD) with Hospital Episode Statistics (HES)-linked data were included if they had an ACS-related hospitalization (January 2008-December 2009). Logistic regression analyses were used to assess what characteristics at ACS-related hospitalization date were associated with PCI or MM classified at 30-days post-hospitalisation date (30DHD). RESULTS: 10,753 ACS patients were identified (60% male, 67% aged ≥ 65, 81% had NSTEMI or UA at index date). 30DHD, 74% were MM and 26% had PCI. Factors associated with receiving PCI were STEMI at hospitalization (OR 3.73, 95% CI 3.30, 4.22); patients with previous PCI pre-hospitalization (OR 1.29, CI 1.07, 1.55) and current smokers (OR 1.16, CI 1.02, 1.32). Patients less likely to receive  PCI included women (OR 0.67, CI 0.60, 0.75), those with previous ACS hospitalization (OR 0.69, CI 0.59, 0.80), those prescribed: statins  12 months pre-hospitalization date (OR 0.75, CI 0.67, 0.85), diuretics (OR 0.72, CI 0.61, 0.85), ACE inhibitors (OR 0.84, CI 0.75, 0.95), proton pump inhibitors (OR 0.86, CI 0.77, 0.96), those previously diagnosed with congestive heart disease (OR 0.54, CI 0.42, 0.71), atrial fibrillation (OR  0.67, CI 0.54, 0.83), stroke/TIA (OR 0.77, CI 0.63, 0.93) or renal disease (OR 0.82, CI 0.71, 0.95). Age and BMI were significant as continuous variables with non-linear effects. CONCLUSIONS: This is the first large-scale UK study using real-world data to assess socio-demographic and clinical predictors for PCI in ACS, and indicates that NSTE-ACS patients and those with comorbidities are more likely to be MM. This will be discussed in light of current treatment of STEMI and NSTE-ACS in the EU.