In order to analyse both sexual desire after menopause and its response to treatment with tibolone, a randomized placebo/tibolone trial has been designed with 28 postmenopausal patients. They were asked to answer a questionnaire designed by us to obtain quantitative measurements to describe changes in sexual desire. After selection, the patients were randomly assigned to two groups as follows: 14 in the group treated with 2.5 mg/day of tibolone and 14 in the placebo group treated with 500 mg/day of calcium. The patients were monitored after 3, 6 and 12 months. Before joining this study, they had signed a written consent. It was observed that the sexual desire after menopause underwent a significant fall, with decline in arousability and intercourse. The comparative results show that the patients treated with tibolone experience an improvement after the third month of treatment and this improvement was maintained until the end of treatment. We conclude that the questionnaire proposed here is a useful non-parametric method to diagnose a patient's sexuality status at the baseline assessment and a valuable tool for monitoring various therapies. Furthermore, tibolone proved to be effective in managing reduced sexual desire which appears in postmenopausal patients.