Although the European Court of Human Rights adopted a new policy in 2004 to balance gender, women are still underrepresented in the Court. Women's representation in the international courts is crucial not only because half of the population in the world is female but also women's ability to act as a kind of bridge for other underrepresented groups such as older people, children, racial and religious minorities. This paper studies the effect of gender of judges in the ECHR. It focuses on whether female judges decide differently than male judges and whether the European Union membership plays any role in the selection of judges. I will use causal inference methods to present this effect.