This text questions the important role played by two major environmental NGOs, CI and WWF, in the process of defining and governing two protected areas located in the northern province of New Caledonia. With its unique legal status, this atypical Pacific territory of French overseas territories, now recognized as a hotspot for biodiversity (Myers et al., 2000), is indeed in the middle of a unique process of negotiated decolonization. This includes skills transfers from France to this "non-decolonized former colony" (Demmer and Salomon, 2013) that have already allowed the emergence of the preservation of biodiversity as a major political issue. With the concomitant inclusion of environmental concerns in international agendas, and very much like in other territories (Aubertin 2005, Léna 2002), several non-governmental conservation organizations (NGOs) have gradually contributed to the definition of environmental issues and local environmental public policies. Based on two case studies, this text shows the mechanisms by which these NGOs initially took part in the process of reviewing the former parks and natural reserves of the territory before becoming privileged partners of the local institutions.