Objective In statin-treated patients with stable coronary artery disease (CAD), residual risk of cardiovascular events is partly explained by plasma levels of low-density lipoprotein cholesterol (LDL-C). This study aimed to estimate individual benefit of proprotein convertase subtilisin/kexin type 9 (PCSK9) inhibition in CAD patients already treated with high-dose statin. Methods Individual lifetime benefit was estimated in months gain free of stroke or myocardial infarction (MI) until age 80 years. Predictions were based on two competing risk models developed in data from 4853 patients with CAD originating from the atorvastatin 80 mg arm of the Treating to New Targets (TNT) trial. The relative effect of PCSK9 inhibition was added to the models and was assumed based on average estimates from large clinical trials. We accounted for individual LDL-C levels, assuming 50% LDL-C reduction by PCSK9 inhibition and 21% cardiovascular risk reduction per mmol/L (39 mg/dL) LDL-C lowering. Results Estimated individual gain was <6 months in 61% of the patients, 6-12 months in 28% of the patients and ≥12 months in 10% of the patients (median 5, quartiles 2-8 months). Highest estimated benefit was observed in younger patients (aged 40-60 years) with high risk factor burden, particularly if LDL-C levels were >1.8 mmol/L (>70 mg/dL). Estimated benefit was lowest (≤5 months) in older patients (≥70 years), in particular if LDL-C and other risk factors levels were low. Conclusion The individual estimated lifetime benefit from PCSK9 inhibition in patients with stable CAD on high-dose statin varied from <6 to ≥12 months free of stroke or MI. Highest benefit is expected in younger patients (age 40-60 years) with high risk factor burden and relatively high LDL-C levels.