Subclinical hypothyroidism is characterized by normal serum levels of free thyroxine and triiodothyronine with increased serum levels of thyroid-stimulating hormone (TSH) without symptoms. We evaluated by thoracic electrical bioimpedance cardiography the hemodynamic pattern of 38 patients with subclinical hypothyroidism, before and after 6-month therapy with levo(L)-thyroxine. We have not evidenced statistically significant differences for cardiac index, cardiac frequency and vascular peripheral resistances. TSH levels were decreased in a statistically significant way. Results obtained in our study show that hemodynamic pattern is not changed after hormone therapy in patients affected by subclinical hypothyroidism.