Little is known about non-monosexual women's sexual arousal and desire. Typically, bisexual women have been excluded from research on sexual arousal and desire, whereas mostly heterosexual and mostly lesbian women have been placed into monosexual categories. This research (1) compared the subjective sexual arousal and desire of self-identified heterosexual, mostly heterosexual, bisexual, mostly lesbian, and lesbian women in partnered sexual activities with men and with women, and (2) compared within-group differences for subjective sexual arousal and desire with men versus women for the five groups. Participants included 388 women (M age = 24.40, SD = 6.40, 188 heterosexual, 53 mostly heterosexual, 64 bisexual, 32 mostly lesbian, 51 lesbian) who filled out the Sexual Arousal and Desire Inventory (SADI). Sexual orientation was associated with sexual arousal and desire in sexual activities with both men and with women. Bisexuals reported higher sexual arousal and desire for women than heterosexuals and lesbians, while lesbians reported lower sexual arousal and desire with men than the other groups. Heterosexuals and mostly heterosexuals scored higher on the male than on the female motivational dimension of the SADI, while the reverse was found for lesbians and mostly lesbians. Findings indicate that non-monosexuals have higher sexual arousal and desire in sexual activities with women than monosexuals. Further, bisexual women did not differentiate their sexual arousal with men versus women, while the other sexual orientation groups differentiated in terms of their motivation to engage in sexual activity. These findings may have implications for how female sexual orientation is conceptualized.