Autosomal dominant polycystic kidney disease (ADPKD) is the most common hereditary kidney disorder and is characterized by the progressive development of multiple bilateral renal cysts and the deterioration of renal function. Patients with ADPKD also have a substantially elevated risk of diverse systemic vascular complications such as intracranial aneurysm (IA), a serious life‑threatening condition. IA occurs much more frequently in patients with ADPKD than in the general population, and IA rupture can lead to subarachnoid hemorrhage, a major cause of mortality and long‑term disability. Although clinical evidence supports an association between ADPKD and IA, the exact nature of the molecular and pathological connections between these conditions remains unclear, making it difficult to develop effective preventive and therapeutic strategies. Advances in vascular biology have led to the view that endothelial dysfunction is a pivotal event in the pathogenesis of multiple vascular diseases. Consequently, there is increasing attention on the role of endothelial dysfunction in mediating the relationship between ADPKD and IA. The present review first summarizes the physiological functions and structural characteristics of endothelial cells, and then focuses on the pathological effects of endothelial dysfunction in ADPKD and IA. Additionally, the review describes therapeutic strategies that aim to restore endothelial function, with a focus on the use of early screening and precision treatment, to improve the prognosis of patients with ADPKD complicated by IA.