Glutamate excitotoxicity is intricately linked to the pathogenesis of neurodegenerative diseases, exerting a profound influence on cognitive functions such as learning and memory in mammals. Glutamate, while crucial for these processes, can lead to neuronal damage and death when present in excessive amounts. Our previous review delved into the cascade of excitotoxic injury events and the underlying mechanisms of excitotoxicity. Building on that foundation, this update summarizes the latest research on the role of excitotoxicity in neurodegenerative diseases such as Alzheimer's disease, Parkinson's disease, Huntington's disease, and amyotrophic lateral sclerosis, as well as new cutting-edge techniques applied in the study of excitotoxicity. We also explore the mechanisms of action of various excitotoxicity inhibitors and their clinical development status. This comprehensive analysis aims to enhance our understanding of the nexus between excitotoxicity and neurodegenerative diseases, offering valuable insights for therapeutic strategies in these conditions.