Intimate partner violence against women (IPVAW) is a public health and social responsibility issue affecting women worldwide. The role of society is essential to help victims to get out of the violent relationship and reduce their risk of revictimization. In this regard, the social response to IPVAW depends to some extent on public beliefs and attitudes toward IPVAW. Hence, this research explores the direct relationship between sexism and the willingness to intervene in cases of IPVAW, indirectly through acceptance of myths of IPVAW, perceived severity of IPVAW, risk assessed of victims’ health and life as well as to the establishment of equal relations, attribution of the responsibility to the aggressor, and victim blaming. A Spanish sample of 487 participants was collected through incidental sampling. Participants responded to an online survey that was disseminated via email and social media. A parallel path analysis model showed that greater sexism was associated with lower willingness to intervene in cases IPVAW, via greater acceptance of the myths of IPVAW and less attribution of responsibility to the aggressor. IPVAW perceived severity, risk assessed, and victim blaming did not explain the effect of sexism on willingness to intervene. This research emphasizes the need to focus on egalitarian education that mitigates sociocultural risk factors such as patriarchal beliefs and attitudes that explain IPVAW and favors a climate of acceptance and tolerance of this problem, making it difficult for victims to break with the violent relationship.