Abstract: Objectives: To elucidate if percutanous treatment with 10mg testosterone per day could enhance sexuality and psychological well-being in postmenopausal women presenting problems with low libido. Secondary to study the influence on blood lipids, hemoglobin and erythropoietin levels. Methods: Fifty-three postmenopausal women participated. As a complement to their already on-going HRT, 10mg of a testosterone gel (Testogel, Besins–Iscovesco) or placebo was administered. Treatment continued for three plus three months in a double blind, randomized, crossover design. Results: The scores concerning “frequency of sexual activity, orgasm and intercourse”, “sexual arousal, fantasies and enjoyment”, “satisfaction with orgasms”, and “interest in sex” were all significally improved for testosterone addition as compared to placebo both before and after crossover. Testosterone levels increased more than 10-fold during treatment while DHT-levels were more than doubled. Estrogen levels were not affected during the addition of testosterone. Liver enzymes, total cholesterol, triglycerides, HDL and LDL revealed no significant differences between any of the periods or groups. Endometrial thickness did not change significantly during treatment. Hemoglobin and erythropoietin remained unchanged. No significant differences in the number of experienced side effects were found. Conclusion: Testosterone gel of 10mg had positive effects on several aspects of sexual life such as frequency of sexual activity, orgasm, arousal, fantasies and sexual interest in postmenopausal women on HRT. Several psychological variables were positively influenced. The given dose resulted in too high serum levels. Even if no negative effects were observed, monitoring of serum levels and a decreased dose should be considered in future studies. [Copyright &y& Elsevier]