Stereotypes are generalizations about attributes, traits and behaviors which belong to a group. Although it is accepted their usefulness in practical social life, they can create distortions and consequently lead to damage when, on failing to consider the specificities of certain persons or groups, support the denial of their rights. In a patriarchal society where woman was constructed in relation to men, gender stereotypes contribute to create and reinforce gender hierarchies that operate against women. In the case of Brazilian women prisoners, we can see how stereotypes act to criminalize them twice by observing the prisons conditions to which they are subjected. The reality of prisoners shows that the stereotype of women as weak and passive when broken generates greater social disapproval, so their criminality seems to be more severe than that of men. There are two aspects that must necessarily be regarded in the study of women s imprisonment: women s custody prior to the penal system, embodied by a policy of informal control implemented by the family, and the intersection between the multiple focuses of discrimination that women in prison suffer. Being Law an institution where gender stereotypes are reproduced, this work aims at questioning to what extent it can be an instrument of struggle for equality, recognizing the urgency in building and enhancing some feminist criminology that can transform the practices of gender that have prevented incarcerated woman to receive adequate treatment.