The aim of the present paper was to test differences in perceptions towards a woman who took a 3-month maternity leave (a working mother) as opposed to a 3-year maternity leave (a stay-at-home mother), and then to apply the ambivalent sexism theory to predict those differences. We expected that in Poland, where motherhood is highly appreciated, it is especially benevolent (not hostile) sexism that predicts less positive attitudes toward working mothers, compared to stay-at-home mothers. In two studies, we found that the working mother was perceived as less warm, less effective as a parent and less interpersonally appealing and more successful at work. Additionally, although the stay-at-home mother was evaluated as less successful at work, she was not perceived as less competent. We discuss this as a reflection of the “Mother-Pole” phenomenon, where mothers in Poland are perceived as not only kind, but also competent. Afterward, we showed that benevolent (but not hostile) sexism predicts differences in perceiving the stay-at-home mother and working mother. Participants higher in benevolent sexism rated the stay-at-home mother as warmer, more parenting-effective and more interpersonally appealing compared to the working mother, while participants lower in benevolent sexism perceived them equally well. Studies suggest that benevolent sexism predicts a more positive perception of traditional mothers (as opposed to nontraditional mothers), and at the same time, maintains the status quo of traditional gender relations.