OBJECTIVE: Diabetes mellitus is an established risk factor for sexual dysfunction in men, but its effect on female sexual function is poorly understood. We examined the relationship of diabetes to sexual function in middle-aged and older women. METHODS: Sexual function was examined in a cross-sectional cohort of ethnically diverse women aged 40-80 years using self-administered questionnaires. Multivariable regression models compared self-reported sexual desire, frequency of sexual activity, overall sexual satisfaction, and specific sexual problems (difficulty with lubrication, arousal, orgasm, or pain) among insulin-treated diabetic, non-insulin-treated diabetic, and nondiabetic women. Additional models assessed relationships between diabetic end-organ complications (heart disease, stroke, renal dysfunction, and peripheral neuropathy) and sexual function. RESULTS: Among the 2,270 participants, mean±standard deviation age was 55±9.2 years, 1,006 (44.4%) were non-Latina white, 486 (21.4%) had diabetes, and 139 (6.1%) were taking insulin. Compared with 19.3% of nondiabetic women, 34.9% of insulin-treated diabetic women (adjusted odds ratio [OR] 2.04, 95% confidence interval [CI] 1.32-3.15) and 26.0% of non-insulin-treated diabetic women (adjusted OR 1.42, 95% CI 1.03-1.94) reported low overall sexual satisfaction. Among sexually active women, insulin-treated diabetic women were more likely to report problems with lubrication (OR 2.37, 95% CI 1.35-4.16) and orgasm (OR 1.80, 95% CI 1.01-3.20) than nondiabetic women. Among all diabetic women, end-organ complications such as heart disease, stroke, renal dysfunction, and peripheral neuropathy were associated with decreased sexual function in at least one domain. CONCLUSION: Compared with nondiabetic women, diabetic women are more likely to report low overall sexual satisfaction. Insulin-treated diabetic women also appear at higher risk for problems such as difficulty with lubrication and orgasm. Prevention of end-organ complications may be important in preserving sexual activity and function in diabetic women. LEVEL OF EVIDENCE: II.