Aim. To evaluate sexual function among postmenopausal diabetic women. Patients and methods. A total of 72 postmenopausal women, 36 diabetic, with a stable partner were included in this study. Sexual functioning was assessed using the Female Sexual Functioning Index (FSFI) and depression using the Beck Depression Inventory scale. Results. There was no difference between diabetic and control women regarding age, years of schooling, number of children, age at menarche, age at first sexual experience, years postmenopausal or body mass index. Diabetics had a worse score for depression (11.5±5.6 vs. 8.9±4.7, p<0.03), a lower frequency of sexual intercourse per month (2.7±2.8 vs. 4.4±2.9, p<0.01) and a more deteriorated marital relationship (scale of 0-20: 13.4±2.9 vs. 15.1±1.9, p<0.009). Diabetics demonstrated worse scores globally (19.3±8.1 vs. 26.8±4.5, p<0.0001) and in all domains of the FSFI: desire (2.6±1.4 vs. 3.8±1.1, p<0.0001), arousal (3.5±1.9 vs. 4.7±0.8, p<0.002), lubrication (3.2±1.9 vs. 4.5±1.3, p<0.003), orgasm (3.2±1.8 vs. 4.5±1.1, p<0.002), satisfaction (3.8±1.3 vs. 4.8±0.9, p<0.0005) and pain (3.1±1.7 vs. 4.6±1.3, p<0.0001) (values all mean±standard deviation). Considering sexual dysfunction as a score higher than 26.55, the prevalence of sexual dysfunction among diabetics was 75.0% vs. 30.6% in the control group (p<0.001). After adjusting for depression, years of schooling, hysterectomy, marital relationship and age, diabetes mellitus remained an important risk factor for sexual dysfunction (odds ratio 6.2, 95% confidence interval 2.0-19.6, p<0.02). Conclusion. Diabetes mellitus affects all areas of female sexuality and this condition is independent of depression.