Women demonstrate stronger preferences for femininity when assessing men's attractiveness for long-term rather than short-term relationships. One explanation of this effect is that the pro-social traits associated with femininity are particularly important for long-term relationships. This explanation has recently been challenged, however, following null findings for effects of pro-social attributions on women's preferences for feminine long-term partners. A limitation of these latter analyses is that they did not consider hormonal contraceptive use, which is a factor that previous studies suggest affects mate preferences. In our study, we found that women not using hormonal contraceptives demonstrated stronger preferences for femininity in men's faces when assessing men as long-term partners than when assessing men as short-term partners. Moreover, this effect was most pronounced among women who perceived feminine men as particularly trustworthy. No equivalent effects were observed among women using hormonal contraceptives. These findings support the proposal that the effect of relationship context on women's face preferences occurs, at least in part, because women value pro-social traits more in long-term than short-term partners. Additionally, our findings suggest that both hormonal contraceptive use and individual differences in perceptions of pro-social traits modulate the effect of relationship context on women's face preferences.