BACKGROUND: Whether a strategy to target an LDL (low-density lipoprotein) cholesterol <70 mg/dL is more effective when LDL is reduced >50% from baseline rather than <50% from baseline has not been investigated. METHODS: The Treat Stroke to Target trial was conducted in France and South Korea in 61 sites between March 2010 and December 2018. Patients with ischemic stroke in the previous 3 months or transient ischemic attack within the previous 15 days and evidence of cerebrovascular or coronary artery atherosclerosis were randomly assigned to a target LDL cholesterol of <70 mg/dL or 100±10 mg/dL, using statin and/or ezetimibe as needed. We used the results of repeated LDL measurements (median, 5 [2–6] per patient) during 3.9 years (interquartile range, 2.1–6.8) of follow-up. The primary outcome was the composite of ischemic stroke, myocardial infarction, new symptoms requiring urgent coronary or carotid revascularization, and vascular death. Cox regression model including lipid-lowering therapy as a time-varying variable, after adjustment for randomization strategy, age, sex, index event (stroke or transient ischemic attack), and time since the index event. RESULTS: Among 2860 patients enrolled, patients in the lower target group who had >50% LDL cholesterol reduction from baseline during the trial had a higher baseline LDL cholesterol and a lower LDL cholesterol achieved as compared to patients who had <50% LDL cholesterol reduction (155±32 and 62 mg/dL versus 121±34 and 74 mg/dL, respectively, P <0.001 for both). In the <70 mg/dL target group, patients with >50% LDL reduction had a significant reduction in the primary outcome as compared to the higher target group (hazard ratio, 0.61 [95% CI, 0.43–0.88]; P =0.007) and patients with <50% LDL reduction from baseline had little reduction (hazard ratio, 0.96 [95% CI, 0.73–1.26]; P =0.75). CONCLUSIONS: In this post hoc analysis of the TST trial, targeting an LDL cholesterol of <70 mg/dL reduced the risk of primary outcome compared with 100±10 mg/dL provided LDL cholesterol reduction from baseline was superior to 50%, thereby suggesting that the magnitude of LDL cholesterol reduction was as important to consider as the target level to achieve. REGISTRATION: URL: https://www.clinicaltrials.gov ; Unique identifier: NCT01252875. URL: https://clinicaltrialsregister.eu ; Unique identifier: EUDRACT2009-A01280-57.