Objective: The aim of this study was to assess whether subclinical hypothyroidism (SCH) is associated with carotid atherosclerosis, as well as dyslipidemia, and arterial hypertension. Subjects and methods: The study included 69 consecutive patients with newly diagnosed SCH, and 30 matched healthy controls. Body mass index (BMI), TSH, fT4, antibodies to thyroid peroxidase (TPOabs), lipids, blood pressure, mean and maximum carotid intima-media thickness (CIMT) were determined in all participants. Results: Mean values of CIMT, triglycerides, and total cholesterol/HDL-C ratio were significantly different in SCH patients versus matched controls. Linear multiple regression analysis demonstrated that TSH, diastolic blood pressure and triglycerides were independent predictors of mean CIMT, fT4 for maximum CIMT; and that TSH, fT4, age, and total cholesterol/HDL-C ratio were independent predictors of the presence of carotid plaques. Conclusion: Our data revealed that SCH is associated with increase in CIMT and presence of carotid plaques, independent of classical risk factors for atherosclerosis. Arq Bras Endocrinol Metab. 2011;55(7):475-80 Keywords Subclinical hypothyroidism; atherosclerosis; dyslipidemia; arterial hypertension; carotid intima-media thickness ReSumoObjetivo: O objetivo deste estudo foi avaliar se o hipotireoidismo subclínico (HSC) está associado a aterosclerose de carótida, dislipidemia e hipertensão arterial. Sujeitos e métodos: O estudo incluiu 69 pacientes consecutivos recém-diagnosticados com HSC e 30 controles pareados. Índice de massa corpórea, TSH, T4L, anticorpos antiperoxidase (TPO), perfil lipídico, pressão arterial, espessamento carotídeo íntima-média máximo (ECIM) e médio foi determinado em todos os indivíduos. Resultados: Os valores médios de ECIM, triglicérides e razão colesterol total/C-HDL foram significantemente diferentes entre pacientes e controles. Regressão linear múltipla demonstrou que TSH, pressão arterial diastólica e triglicérides foram fatores independentes preditores de ECIM médio, T4L para ECIM máximo e TSH, T4L, idade e colesterol total/HDL-C para presença de placa carotídea. Conclusão: Nossos resultados indicam que HSC é associado com aumento do ECIM e presença de placas carotídeas, independentemente dos fatores de risco clássicos para aterosclerose. Arq Bras Endocrinol Metab. 2011;55(7):475-80 Descritores