Objective: This study aimed to find the relationship between intima-media thickness and proteinuria, which are early findings of atherosclerosis and renal failure in patients with metabolic syndrome.Methods: In our study, 63 patients with metabolic syndrome and 26 healthy subjects, as the control group, were involved. Both groups were over 40 years old in the study. In both groups, carotid intima-media thickness was measured with B-mode ultrasonography. All biochemical data were analyzed retrospectively.Results: Overall, 61.9% of patients were women; 38.1% of them were men. Also, 61.54% of the control group was female; 38.46% of them were men. Carotid intima-media thickness, level of glucose, urea, creatinine, high-density lipoprotein (HDL) cholesterol, uric acid, C-reactive protein (CRP), retinopathy (p<0.001), age (p=0.017), triglyceride (p=0.022), glomerular filtration rate (GFR) (p=0.029), proteinuria (p=0.035), abdominal circumference (p=0.006), body mass index (BMI) (p=0.047), and thyroid-stimulating hormone (TSH) (p=0.013) were significantly higher in patients with metabolic syndrome.Conclusion: In the patients with metabolic syndrome, carotid intima-media thickness and proteinuria are precursors of atherosclerosis. These findings are important predictions for the development of type II diabetes mellitus, coronary heart disease, and chronic kidney disease.