In Europe, the decisions of the Court of Justice of the European Union (CJEU) and the European Court of Human Rights (ECtHR) develop influence that transcends the particular case at hand. While this development has been criticised by progressive scholars, this thesis argues that it also enables civil society to participate in judicial decision making processes. In the context of Lesbian, Gay, Bi and Transgender (LGBT) rights, this thesis investigates whether "strategic litigation" before the European High Courts can be a feasible and emancipatory endeavor. The concept of "strategic litigation" - developing long-term litigation strategies in order to induce legal, social and/or political reform - is based on the recognition that adjudication is, to a large extent, a political process. To this end, strategic litigation as a (political) strategy is introduced and positioned within legal theory and the literature on "cause lawyering." Within Europe, this thesis focuses on the ECtHR and the CJEU as potential fora for strategic litigation. In order to assess their case law from an activist point of view, a "strategic litigation opportunities" framework is designed. This framework both illuminates indicators for activist intervention, and highlights the agency of LGBT rights advocates in litigation. By doing so, it challenges the view of adjudication as a purely “top-down” process. Lastly, a case study on the US LGBT rights movement, and the effective strategic litigation on (same-sex) marriage equality it has engaged in, serves as an example for the successful application of a long-term cause lawyering approach. Ultimately, this thesis will conclude that strategic LGBT rights litigation at the European High Courts can, indeed, be a feasible and emancipatory endeavour, by establishing: 1) European High Courts exert quasi-legislative power. 2) European High Courts provide procedural spaces for activist LGBT rights lawyers. 3) The European High Courts’ case law can be analysed and utilised in a progressive LGBT-rights enhancing way.