The loss of sexuality observed in the climacteric period is difficult to evaluate. An important advance has been the development of the Female Sexual Function Index (FSFI), a test based on the norms of the International Consensus Development Conference on Sexual Female Dysfunctions. Aim: To study the effects of hormone replacement therapy (HRT) on sexuality, applying the FSFI. Material and methods: The FSFI was applied to 300 healthy women between 45-64 years, sexually active, beneficiaries of the Southern Metropolitan Health Service. Results: The mean age of the sample studied was 51±5 years, 27% were HRT users, 21% had had an hysterectomy and 98% had a stable couple. The total score of the FSFI decreased from 27.3±5.8 in women between 45 and 49 years of age to 19.3±7.0 in women between 60 and 64 years (p <0.01). A significantly better sexuality was observed in HRT users, with FSFI scores of 28.1±5.5 and 24.6±6.8 in HRT users and non users, respectively (p <0.01). Women on HRT obtained a higher score in all of the test domains, especially in lubrication, orgasm and sexual satisfaction. Conclusions: Female sexuality decreases with aging. HRT users have a better sexual function than non users (Rev Méd Chile 2003; 131: 1251-55 )