Abstract During the international tuna fishery management crisis in 2009, an epistemic community emerged at the International Commission for the Conservation of Atlantic Tunas (ICCAT) that employed collective efforts to deal with shared problems and improved the effectiveness of agreements, in terms of the recovery of Eastern Blue Fin Tuna (EBFT) stocks. This event resulted in the question: when and why does power listen to science? Through a combination of elite interviews and process tracing, this investigation analyzed the roles and influences of science and epistemic communities in the ICCAT EBFT political decisions, from 2004 to 2014. We have concluded that the EBFT case illustrates a situation where effective agreements to handle a fishery crisis in an uncertain environment were enhanced, when a transnational network of non-governmental organizations (NGOs) and the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES), helped to pressure the decision-makers.