Background: Carotid artery stenting is increasingly being selected as the treatment for severe (≥70%) carotid artery stenosis, creating a growing need to prevent potential secondary complications associated with the procedure. In-stent restenosis (ISR) remains an important complication during long-term follow-up after carotid artery stenting. In this clinical case, we have addressed risk factors, pathogenesis, diagnosis, treatment, and monitoring of in-stent restenosis. Case Presentation: We describe the case of a 70-year-old man with severe, symptomatic IRS detected 1.8 years after carotid artery stenting (CAS). Conclusion IRS following carotid artery stenting is a clinically significant complication that may adversely affect cerebral perfusion and increase the risk of recurrent ischemic stroke. Early detection and follow-up with carotid duplex ultrasonography, regular follow-up, and lifestyle modifications, particularly smoking cessation, are essential for prevention of adverse cerebrovascular events.