The purpose of this study is to examine whether the high level of women's representation in politics contributes to change the patriarchal values in societies of Rwanda and Japan. There are many works on women's representation in parliament, but most studies focused on the causes of their under-representation. Also, most of the case studies have been conducted inside the Western context. With face to face interviews with female Parliamentarians in Rwanda and Japan, the study revealed positive effects of female political representation on patriarchal values. Although Rwandan society is still patriarchal, the increased number of female MPs in the Lower House contributed to the change in laws underpinning patriarchal norms (especially with regard to women's access and control over property, education and gender-based violence), and changed the community's attitude toward women's ability and leadership skills. As the Japanese society does not have a quota system yet, the presence of women in Lower House is very low and this facilitate the society in maintaining patriarchal values unchanged. Furthermore, the findings of this study demonstrate that state's political commitment and women's political organization in Rwanda have been at the base of these achievements.