Objective. Limited data are available regarding the relationship of thyrotropin (TSH) and arterial pulse wave velocity (PWV) at population level. Therefore, we conducted the present study to determine whether TSH is related to PWV assessed in young adulthood. Methods. The study population consisted of 1598 Finnish white young adults (aged 30-45 years, 47.4% males) who had TSH, traditional cardiovascular risk factors, and PWV measured in 2007. PWV measurements were performed using a whole-body impedance cardiography device. Results. In bivariate association analyses, TSH level was significantly associated with body mass index (BMI), smoking, diastolic blood pressure, triglyceride and insulin levels (p < 0.001). In multivariable regression model, TSH (β = 0.055, p = 0.015) was associated with PWV when adjusted with age (β = 0.295, p < 0.001) and sex (β = 0.345, p < 0.001). The association of TSH with PWV was however diluted to non-significant after further adjustment with traditional risk factors (β = 0.027, p = 0.218 for TSH). Conclusion. Serum TSH was associated with PWV on population level when adjusted with age and sex. This association was diluted when cardiovascular risk factors were added in the model, suggesting that the association of thyroid hormone on arterial stiffening is not independent of changes in the traditional risk factor levels.