Neurological deterioration following acute ischemic stroke (AIS) is a common clinical phenomenon associated with poor clinical outcomes. However, neurological deterioration can be attributed to diverse mechanisms in different clinical contexts. Further, there is still a lack of standard and well-recognized definitions of neurological deterioration, which compounds the complexities and challenges of its early identification and management of neurological deterioration. As AIS becomes increasingly common, the need to address neurological deterioration after AIS in clinical practice and further improve functional outcomes is becoming more urgent.To facilitate earlier recognition and more precise interventions, in this review, we comprehensively outline the evolution of the definition of neurological deterioration, its incidence in various patient groups, and the potential underlying causes rooted in multiple pathophysiological mechanisms. We further highlight the diverse risk factors associated with neurological deterioration and provide an overview of the scientific basis and practical applications of preventative and therapeutic strategies.Early identification and management of neurological deterioration in AIS patients is crucial but challenging due to lack of unified assessment criteria and diverse mechanisms. Standardizing definitions and developing targeted strategies based on pathological mechanisms and pharmacological profiles are needed to improve outcomes.© 2025 S. Karger AG, Basel.