Premenstrual dysphoric disorder (PMDD) is an important women's mental health issue. This study aimed to investigate the association between Internet use disorder (IUD), PMDD, and their associated factors, such as stress and impulsivity. Women with PMDD (n = 79) and controls (n = 76) were recruited from the community. The diagnoses of PMDD and IUD were confirmed by psychiatric interviews. Participants were evaluated with the Chen Internet Addiction Scale, Perceived Stress Scale, and Barratt Impulsiveness Scale in both the premenstrual and follicular phases. Women with PMDD were more likely to have IUD. Women with PMDD had greater severity of IUD, perceived stress, and impulsivity than the control group in the premenstrual phase. Impulsivity mediated the association between PMDD and IUD, while both impulsivity and perceived stress mediated the association between PMDD and IUD severity. Thus, IUD should be evaluated and treated among women with PMDD, particularly for those with higher impulsivity or higher perceived stress. Strategies for stress management and counseling for impulsivity should be provided to women with PMDD, particular to those comorbid with IUD.