Sexual difficulties in women appear to be widespread in society; the relationship between female sexual function and obesity is unclear. This study aimed to investigate the relationship between body weight, the distribution of body fat and sexual function in women. Fifty-two, otherwise healthy women with abnormal values of female sexual function index (FSFI) score (< or =23) were compared with 66 control women (FSFI >23), matched for age and menopausal status. All women were free from diseases known to affect sexual function. FSFI strongly correlated with body mass index (BMI) (r=-0.72, P=0.0001), but not with waist-to-hip ratio (r=-0.09, P=0.48), in women with sexual dysfunction. Of the six sexual function parameters, desire and pain did not correlate with BMI, while arousal (r=-0.75), lubrication (r=-0.66), orgasm (r=-0.56) and satisfaction (r=-0.56, all P<0.001) did. FSFI score was significantly lower in overweight women as compared with normal weight women, while cholesterol and triglyceride levels were higher. On multivariate analysis, both age and BMI explained about 68% of FSFI variance, with a primacy of BMI over age (ratio 4:1). In conclusion, obesity affects several aspects of sexuality in otherwise healthy women with sexual dysfunction.