Aims: Despite patient reports of neurocognitive disorders with lipid-lowering treatments (LLTs), large clinical trials have found no significant association between neurocognitive disorders and LLTs. We assessed incidence of neurocognitive treatment-emergent adverse events (TEAEs) from 14 Phase 2 and 3 trials of the proprotein convertase subtili-sin/kexin type 9 (PCSK9) inhibitor alirocumab. Methods and results: Patients (most on background maximally tolerated statin) received alirocumab 75/150 mg every 2 weeks (n = 3340; 4029 patient-years of exposure), placebo (n= 1276),orezetimibe (n= 618). Data were pooled by the control used. Neurocognitive TEAEs were reported by 22 (0.9%) alirocumab-treated patients vs. 9 (0.7%) with placebo in placebo-controlled trials [hazard ratio (HR) 1.24, 95% confidence interval (CI) 0.57-2.68] and 10 (1.2%) with alirocumab vs. 8 (1.3%) with ezetimibe in ezetimibe-controlled trials (HR 0.81, 95% CI 0.32-2.08). Rates of neurocognitive TEAEs were similar in patients receiving alirocumab with LDL cholesterol (LDL-C) levels <25 mg/dL (<0.65 mmol/L; n= 5/839; 0.6%; 0.5/100 patient-years) vs. ≥25 mg/dL (n = 26/2501; 1.0%; 0.8/100 patient-years). One patient (0.1%; ezetimibe-controlled pool) receiving alirocumab had a neurocognitive TEAE leading to discontinuation vs. two (0.2%) patients receiving placebo and three (0.4%) patients receiving ezetimibe. Neurocognitive TEAE incidence was also similar between alirocumab and controls when stratified by age. Conclusions: Neurocognitive TEAE incidences were low (≤1.2%), with no significant differences between alirocumab vs. controls up to 104 weeks. No association was found between neurocognitive TEAEs and LDL-C <25 mg/dL based on the completed Phase 2 and 3 trials examined, although long-term effects of very low LDL-C levels induced by PCSK9 inhibitors are currently unknown.