The literature on gender and politics has consistently neglected the study of gender inequalities in penal institutions. Our article contributes to filling this gap by examining how gender inequality is represented and framed as a policy problem in the Spanish “Action Program for Gender Equality between Women and Men in the Prison System.” Using critical frame analysis, our findings reveal that gender equality policies in prisons reinforce maternal and caregiving roles, emphasize personal dependency and low self-esteem, and characterize women prisoners as “defective subjects” and “victims,” without adopting an intersectional approach. Our main argument is that the prison system’s failure to embrace the exchange of ideas, involve diverse actors, and engage with civil society, particularly feminist and women’s movements, constrains the formulation process of gender equality policies in this area, and also influences understandings of the issues and the proposed solutions.