Objective <p>This study focused on the characteristics of carotid atherosclerotic plaques using Optical Coherence Tomography (OCT) and compared the plaque features between elderly and young-to-middle-aged patients.</p> Methods <p>Seventy patients with carotid atherosclerotic stenosis underwent carotid OCT examination and were included in the study. Their demographic and clinical data, such as age, gender, coexisting conditions (including hypertension, hyperlipidemia, stroke, and coronary heart disease), smoking and medication histories, and biochemical parameters (fasting blood glucose, triglycerides, total cholesterol, high-density lipoprotein, and low-density lipoprotein) were documented. Additionally, characteristics of the carotid plaques (such as plaque rupture, minimum lumen area, fiber cap thickness, thrombus proportion, fibrous plaque, macrophage infiltration, and calcified plaque) were recorded. Based on age, patients were categorized into an elderly group (&gt; 60 years) and a young-to-middle-aged group (≤ 60 years). Furthermore, they were stratified into symptomatic and asymptomatic groups according to the manifestation of symptoms. Comparisons of the aforementioned indicators were conducted across these groups.</p> Results <p>The elderly group had a higher proportion of plaque rupture than the young-to-middle-aged group (<i>P</i> &lt; 0.05). Additionally, the symptomatic group showed a lower detection rate of fibrous plaque compared to the asymptomatic group (<i>P</i> &lt; 0.05). Conversely, the detection rates of plaque rupture and macrophage infiltration were significantly higher in the symptomatic group (<i>P</i> &lt; 0.05).</p> Conclusion <p>OCT has evaluative value for the characteristics of carotid atherosclerotic stenosis plaques.</p>