Introduction: There is an association between thyroid autoimmunity and the cardiovascular system, however, it remains unclear whether detectability and positivity of thyroid peroxidase antibodies (TPOAb) could contribute to the development of atherosclerosis. Hypothesis: We assessed the hypothesis that there is an association of multiple categories of TPOAb with increased carotid intima-media thickness (cIMT) in participants from the ELSA-Brasil study. Methods: This is a cross-sectional study using baseline data of 9651 participants (mean age of 51.5 years-old, 55.8% women), without a history of cardiovascular disease. Fasting serum TPOAb levels were determined (Roche Diagnostics) and categorized as undetectable (≤ 5.00 IU/mL), low detectable (5.01-14.99 IU/mL), high detectable (15.00-33.99 IU/mL), and positive (34.00-600.00 IU/mL). Values of cIMT above the 75th percentile (≥0.68) were classified as “increased cIMT”. We performed logistic regression models, univariate and adjusted (for sex, age, BMI, smoking, alcohol consumption, diabetes, hypertension, dyslipidemia, and family history of cardiovascular disease), to determine odds ratio (OR) and 95% confidence intervals (CI). Results: Increased cIMT was prevalent in 24.4% of our sample, without statistically significant difference among the categories of TPOAb (p=0.066). Compared to undetectable TPOAb, low detectable category was associated with higher odds of having increased cIMT in univariate (OR=1.37, CI= 1.04-1.82) and remained associated after the adjustment for all confounders (OR=1.39, CI= 1.01-1.91). TPOAb high detectability was associated with increased cIMT only in the univariate (OR=1.40, CI= 1.04-1.88) and after adjustment for sex, age and BMI (OR=1.42, CI= 1.02-1.97). No association was seen for TPOAb positivity and cIMT (OR= 1.29, CI= 0.91-1.83). Conclusions: In conclusion, the modest association of low detectable TPOAb with cIMT may suggest a possible role of TPOAb in the atherosclerotic process.