We assessed the independent effects of beta blockers, calcium antagonists, lipid-lowering drugs, angiotensin converting enzyme inhibitors (ACEIs), angiotensin receptor blockers (ARBs), anti-platelet drugs, vitamin K antagonists, percutaneous coronary intervention (PCI) and coronary artery by-pass grafting (CABG) on mortality and on the composite endpoint of death, myocardial infarction, stroke or heart failure in patients with stable angina pectoris. We estimated the effects of the interventions used at baseline by multivariate Cox regression and during follow-up by G-estimation in 7,665 patients followed for a mean of 5 years in the ACTION trial. Adjusted hazard ratios (95% confidence intervals) comparing all cause mortality among users during follow-up to non-users were 1.01 (0.91, 1.09) for beta blockade, 0.82 (0.75, 0.89) for ACEIs or ARBs, 0.93 (0.87, 0.98) for calcium antagonists, 0.54 (0.49, 0.62) for lipid-lowering drugs, 0.49 (0.42, 0.53) for anti-platelet drugs, 0.74 (0.69, 0.78) for PCI, and 0.91 (0.82, 0.98) for CABG. Effects on the composite endpoint were less marked. This observational study confirms that ACEIs or ARBs, lipid-lowering and anti-platelet drugs as used in the everyday management of stable angina have independent secondary preventive effects. Calcium antagonists, PCI and CABG also appear to improve outcome.