Background. Few data exist on the prevalence of FSD in thyroid disorders. Aim. We evaluated FSD in women with thyroid diseases and in control age matched healthy women to investigate the relationship between sexual function, and thyroid hormones. Methods. One hundred and four women with thyroid diseases and 53 controls participated in the study. Eighteen with hyperthyroidism (Group1), 22 hypothyroidism (Group2), 45 Hashimoto's thyroiditis (Group3), 19 nodular goiter (Group4) underwent thyroid function evaluation and sonography. The Female Sexual Function Index (FSFI) assessed sexual function. Results. The prevalence of FSD was 46.1% in thyroid diseases and 20.7% in controls. Only in Group4, the prevalence (68.4 %) was significantly higher than in controls (P < 0.005). The mean total FSFI score were 20.1±7.1 in women with thyroid diseases and 25.6±4.7 in the controls (P<0.001). Compared with controls, there was a significant decrease of desire in Group2; desire, arousal and lubrication in Group3; desire, arousal, lubrication, orgasm and satisfaction in Group4. In thyroid diseases the prevalence of FSD was 53% and 42%, while in the controls was 55% and 20%, in menopausal and pre-menopausal groups, respectively. We found a significant inverse correlation between TSH and FSFI (r =-0.7, P= 0.01) in Group 4, which showed the lowest FSFI score (17.8±5.7) and the highest BMI (28.4±7.1 Kg/m2).Conclusions: Women with thyroid diseases present a higher prevalence of FSD than controls. Although our findings suggest a higher impairment of sexual function in Group4 and a role for TSH in FSD, further researches are needed.