Several lines of evidence suggest that facial-width-to-height ratio (fWHR) provides an accurate cue to men's formidability, thus providing observers with a reliable estimate of their potential success in an interpersonal physical conflict. The degree to which fWHR provides the same information in women's faces, however, remains unclear. In fact, morphological characteristics, such as body size, may be more effective indicators of formidability in women. In the present study, we analyzed the effects of both fWHR and body mass index (BMI) on total number of fights and total number of wins in female competitive Ultimate Fighting Challenge (UFC) fighters. After controlling for number of active years fighting, we found that BMI significantly predicted number of wins in female fighters. The effects of fWHR were not significant, but warrant replication with a larger sample. These results suggest that in women, body size, rather than fWHR, may be a more accurate indicator of success in aggressive interpersonal conflicts. Our findings contribute to a growing body of literature that shows distinct differences in men and women's interpersonal aggressive and dominance behavior, as well as their morphological indicators.