The MO´Ã Foundation in Rio Grande do Sul / Brazil is a Non-Governmental Organization (NGO) of Studies and Research for Environmental Protection and Development and works through actions and projects aimed at Environmental Education. In 2007 the MO´Ã Foundation acquired an area of 24 hectares of Atlantic Forest that was classified as a Private Reserve of Natural Heritage (RPPN), in 2015, after a long and complex process. In Guimarães, Portugal, the Sisterhood of Nossa Senhora do Carmo da owns about 60 hectares of the area where it receives the devotees and promotes the management of green space and the conservation of tourist infrastructure and religious heritage. In 2019, the Municipality of Guimarães submitted the application of Monte da Penha to a locally protected area, in a process still under evaluation by the Institute for the Conservation of Nature and Forests. The work presented aims to infer the role of the private sector in the administration and shared management of protected areas, in a comparative analysis between the MO´Ã Foundation and the Sisterhood of Penha. Based on a systematic review of a database in journals (CAPES, EBSCO, SCIELO, Open Access Scientific Repositories of Portugal), documents, fieldwork and interviews, we conclude that private institutions assume a fundamental relevance in the governance of areas protected, ensuring the main objective of these: the conservation and / or protection of nature in a sustainable way.