The Greek Twinning Experience in the National Assembly of Serbia provided over 100 experts across 10 countries for approximately 100 missions between 2013-2018. The projects aimed to strengthen capacities of parliamentary assemblies in Serbia, Albania, and Turkey regarding EU integration and human rights. Key aspects of the successful projects included adapting to changing political contexts, developing customized recommendations, special reporting, donor coordination, and multi-stakeholder engagement. Lessons learned emphasized the need for dedicated implementation units, managing institutional fatigue, third-party evaluations, and follow-up activities to reinforce gains. The experience highlights the benefits and challenges of EU twinning programs for parliamentary strengthening.