This study investigated carotid artery stenosis (CAS) and associated risk factors in patients with nasopharyngeal carcinoma (NPC) post-radiotherapy.The observation group comprised 86 reexamined patients with NPC, divided into Group 1 and Group 2 based on post-radiotherapy duration, alongside 34 newly diagnosed patients with NPC (Group 0). Carotid artery ultrasonography and chi-square analysis were performed.Moderate-to-severe vascular abnormalities were exclusively in Group 2. Considering mild vascular abnormalities as the standard, the overall vascular abnormality rates in Group 2 and Group 0 were 65.9% and 41.2%, respectively. In Group 2 and Group 0, the abnormality rates for unilateral carotid artery (UCA), common carotid artery (CCA), internal carotid artery (ICA), and external carotid artery (ECA) were 47.4% and 30.9%, 44.3% and 22.1%, 44.3% and 16.2%, and 39.8% and 5.9%, respectively. Comparing group 1 to group 0, only UCA abnormalities were statistically significant (45.4% vs. 30.9%). Considering moderate-to-severe vascular abnormalities as the standard, Group 2 had higher overall vascular, UCA, CCA, ICA, and ECA abnormality rates compared to Group 0. The age at revisit over 45 years, T stage, and N stage may influence CAS.Radiation increasing CAS incidence after 3 years. So, regular examinations are recommended to dynamically monitor CAS after 3 years of radiotherapy.© 2024. The Author(s).