This chapter seeks to examine the inclusion and recognition of gender expertise that occurred during the ratification process of the Council of Europe "Convention on preventing and combating violence against women and domestic violence" (2011) in Poland. It draws on theoretical approaches on gender expertise to identify various feminist knowledge-claims that occurred during the policy debate: scientific, procedural, normative and - to lesser extent - testimonial. The analysis also discovers religious claims that were utilised during the debate. In addition to identifying types of gender expertise, this study aims to understand strategic interactions between gender experts, women’s policy agencies and civil-society actors, highlighting the importance of cooperation between the former in bringing in gender expertise. The chapter concludes with discussing instrumental and symbolic functions of gender expertise, illustrating the challenges and limitations of the gendered character of decision-making processes.