Introduction: While lipid lowering reduces cardiovascular (CV) events, evidence supporting high-intensity lipid lowering among elderly pts is more limited, and recent guidelines recommend moderate rather than high-intensity therapy for pts >75 yrs. We explored age subgroups within the IMPROVE-IT trial to evaluate whether age modified the benefit of adding ezetimibe (EZ) to statin therapy. Methods and Results: The IMPROVE-IT trial demonstrated the combination of EZ and simvastatin (EZ/S) significantly reduced major CV events vs. simvastatin (S) alone in pts with acute coronary syndrome (ACS) and LDL-C between 50 and 125 mg/dL. The primary composite endpoint was CV death, myocardial infarction, stroke, unstable angina requiring hospitalization, and coronary revascularization >30 days. Outcomes according to age were compared in pre-specified subgroups using Kaplan-Meier (KM) analysis and Cox proportional hazards models using age as a continuous variable. Of the 18,144 pts enrolled, 7971 (44%) were 65 yrs or older and 2798 (15%) were 75 yrs or older at randomization. As age increased, event rate increased with KM rates at 7 yrs in the S arm of 30.8% for pts <65 yrs, 39.9% for pts ≥65 yrs, and 47.6% for pts ≥75 yrs. Treatment with EZ/S compared with S resulted in lower event rates in all age groups with an absolute reduction for pts <65 yrs of 0.85% (HR 0.98 CI 0.90-1.05), for pts ≥65 yrs of 3.6% (HR 0.89 CI 0.82-0.96), and for pts ≥75 yrs of 8.7% (HR 0.80 CI 0.70-0.90), with interaction P values of 0.09 and 0.005, respectively. Using age as a continuous variable found event rates for EZ/S vs. S were always lower, but the test for interaction between age and treatment effect for the primary endpoint was non-significant (P=0.15). The rate of gallbladder, liver, and muscle-related adverse events was not increased with EZ/S vs. S among older pts or younger pts. Conclusions: In the IMPROVE-IT trial, pts 65 yrs or older and especially pts 75 yrs or older after ACS derived substantial benefit from higher-intensity lipid lowering therapy with EZ/S compared with S alone, with no increase in safety issues among older age subgroups. These results may have implications for guideline recommendations regarding more intensive lipid lowering in the elderly.