Liquid-liquid phase separation (LLPS) plays a critical role in Alzheimer's disease (AD). Tau and amyloid-β (Aβ) misfolding and aggregation are key pathological features of AD. Recent studies highlight the significance of LLPS in AD pathogenesis. LLPS is influenced by metal ions, small-molecule inhibitors, and protein partners, affecting tau aggregation and toxic oligomerization. LLPS also impacts Aβ aggregation and cross-interactions between amyloidogenic proteins. Techniques used in LLPS research include imaging and microscopy, which help understand its physiological functions. LLPS is involved in various cellular processes, including chromatin architecture, DNA repair, transcriptional regulation, and protein degradation. It is also linked to diseases such as male infertility, prostate cancer, and SARS-CoV-2 infection. AD is characterized by progressive memory loss and cognitive dysfunction. Early detection of amyloid-β and tau deposits is crucial for early intervention. LLPS is associated with neurodegenerative diseases, with tau LLPS being a prominent example. Tau LLPS can be homotypic or heterotypic, influenced by disease-associated mutations and post-translational modifications. Tau LLPS in normal neurons is essential for biological functions and serves as a foundation for tau pathology. Studies show that LLPS promotes tau aggregation, with phosphorylation and mutations accelerating this process. LLPS may mimic the initial stage of abnormal tau aggregation in the brain. Understanding LLPS mechanisms is vital for improving early AD detection and developing treatments. This review summarizes the latest progress in LLPS research in AD, focusing on its role in tau aggregation, Aβ aggregation, and cross-interactions between amyloidogenic proteins.Liquid-liquid phase separation (LLPS) plays a critical role in Alzheimer's disease (AD). Tau and amyloid-β (Aβ) misfolding and aggregation are key pathological features of AD. Recent studies highlight the significance of LLPS in AD pathogenesis. LLPS is influenced by metal ions, small-molecule inhibitors, and protein partners, affecting tau aggregation and toxic oligomerization. LLPS also impacts Aβ aggregation and cross-interactions between amyloidogenic proteins. Techniques used in LLPS research include imaging and microscopy, which help understand its physiological functions. LLPS is involved in various cellular processes, including chromatin architecture, DNA repair, transcriptional regulation, and protein degradation. It is also linked to diseases such as male infertility, prostate cancer, and SARS-CoV-2 infection. AD is characterized by progressive memory loss and cognitive dysfunction. Early detection of amyloid-β and tau deposits is crucial for early intervention. LLPS is associated with neurodegenerative diseases, with tau LLPS being a prominent example. Tau LLPS can be homotypic or heterotypic, influenced by disease-associated mutations and post-translational modifications. Tau LLPS in normal neurons is essential for biological functions and serves as a foundation for tau pathology. Studies show that LLPS promotes tau aggregation, with phosphorylation and mutations accelerating this process. LLPS may mimic the initial stage of abnormal tau aggregation in the brain. Understanding LLPS mechanisms is vital for improving early AD detection and developing treatments. This review summarizes the latest progress in LLPS research in AD, focusing on its role in tau aggregation, Aβ aggregation, and cross-interactions between amyloidogenic proteins.