Intracranial atherosclerosis (ICAS) is a leading cause of ischemic stroke worldwide, with a particularly high prevalence among Asian populations. While early research primarily attributed this to systemic risk factors such as metabolic syndrome, more recent studies highlighted the importance of local factors, including vascular geometry and hemodynamic stress. The pathophysiology of ICAS-related stroke is multifactorial and encompasses in situ thrombotic occlusion, artery-to-artery embolism, hemodynamic compromise, and perforator branch occlusion. A thorough understanding of these mechanisms is essential for precise risk stratification and the development of targeted preventive strategies. Despite advancements in imaging techniques and pharmacological therapies, ICAS continues to present significant clinical challenges. This review synthesizes current knowledge on stroke mechanisms associated with ICAS and discusses emerging evidence for both primary and secondary prevention, including antithrombotic strategies, risk factor modification, and novel imaging approaches such as high-resolution vessel wall magnetic resonance imaging.