This study examined characteristics of self-identified heterosexual women who were concordant or discordant in their sexual behavior and the association of discordance and sexual partnering among those aged 15-44 years from the 2006-2010 National Survey of Family Growth (n = 7,353). Sexual concordance was defined as reporting a heterosexual identity and no female partners in the past year; discordance was reporting a heterosexual identity and having at least one female partner in the past year. Sexual partnering was defined as being concurrent, serially monogamous or monogamous with a male partner in the previous year. Polytomous logistic regression models evaluated the association between sexual discordance and sexual partnering. Among self-identified heterosexual, sexually active women, 11.2 % reported ever having had a same sex partner. Heterosexually discordant women who had both male and female partners in the previous year were 5.5 times as likely to report having a concurrent relationship (95 % CI 2.77-11.09) and 2.4 times as likely to report engaging in serially monogamous relationships (95 % CI 1.19-4.97) with male partners. Discordance between heterosexual identity and same sex behavior is a factor in risky behaviors. Women who have sex with women and men may act as bridges for the transmission of STDs, particularly to their female partners. Sexual education should include information inclusive of non-heteronormative behaviors and identities to provide sexual minorities with the tools and information they need. Clinical guidelines should ensure that all women are offered counseling and screening for reproductive and sexual health.