Objective: The aim of this prospective randomized controlled cross sectional study was to evaluate the effect of a six month tibolone treatment in healthy postmenopausal women on biochemical CVD markers by calculating the changes of the blood serum levels of total cholesterol (TC), low-density lipoprotein (LDL), high-density lipoprotein (HDL), triglycerides (Tg), high-sensitivity C-reactive protein (hsCRP), homocysteine (Hcy), and endothelin-1 (ET-1) at the beginning of the treatment and after six months. Materials and Methods: Fifty-two healthy postmenopausal women were enrolled in a prospective, randomized, case-controlled outpatient trial. Group 1 (n = 26) received 2,5 mg/d tibolone for six months, while Group 2 (n = 26) received no treatment. Serum levels of TC, LDL, HDL, Tg, hsCRP, Hcy, and ET-1 were evaluated at baseline and after six months. Results: The two groups did not statistically differ at baseline characteristics. In Group 1 tibolone treatment decreased significantly TC (p = 0.01), HDL (p < 0.001), and Tg (p < 0.001) serum levels while a significant increase of hsCRP (p < 0.001) was observed. Finally no changes were noticed on LDL, Hcy, and ET-1 serum levels. Regarding Group 2, no changes were observed. Conclusion: Short-term tibolone treatment in healthy postmenopausal women exerts a mixed action, acting beneficially in some markers (TC, LDL, Tg, Hcy, and ET-1) where as detrimentally in others (HDL, hsCRP).