The aims of this prospective study were to compare sexual functioning between women with male partners who have erectile dysfunction (ED) and women without partners with ED and also to investigate the effect of the treatment of male ED on female partner's sexual function. The study included 87 women and their male partners. We divided the women into two groups: 38 women with male partners complaining of ED (ED group) and 49 women with male partners who have no ED (control group). Of the men with ED, 30 were treated with penile prosthesis implantation (n = 17) or oral sildenafil citrate (n = 13). We evaluated all the men with the International Index of Erectile Function (IIEF; Rosen, Cappelleri, Smith, Lipsky, & Pena, 1999), physical examination, and color penile Doppler ultrasound. We evaluated female sexual function with the Female Sexual Function Index (FSFI; Rosen et al., 2000) to assess sexual desire, arousal, lubrication, orgasm, satisfaction, and pain. We compared female sexual function scores between the women of the male partners with and without ED and also compared before both groups and after the treatment of male partners in the ED group. Additionally, we compare the scores according to the type of treatment given to the male partners. Sexual arousal (p = 0.009), lubrication (p = 0.001), orgasm (p = 0.006), satisfaction (p = 0.000), pain (p = 0.039), and total score (p = 0.003) were highly significantly lower in the ED group than in the control group, although sexual desire did not differ between the two groups (p = 0.515). We investigated the effect of male ED on female sexual functions and found no statistically significant differences in the presence of organic type impotence, older age, and lower erection scores on the IIEF (p = 0.53, p = 0.15, and p = 0.1, respectively). After the treatment of male ED, we observed significant improvement in sexual arousal (p = 0.001), lubrication (p = 0.002), orgasm (p = 0.000), satisfaction (p = 0.000), and pain (p = 0.002) in the women. These findings suggest that female sexual function is affected by male erection status and may improve after the treatment of male sexual dysfunction.