After the Rio Summit in 1992, Cameroon and most other countries in Africa adopted principles that have given communities legal rights in the management of natural resources. Mount Cameroon Region presents a typical example where this method of management has been introduced by the Ministry of Forestry and Wildlife in collaboration with International Agencies like GTZ and DED. These institutions introduced ecotourism in 1998 as part of the Mount Cameroon Project (MCP) aimed at conserving biodiversity and improving the livelihood of the communities in this area. Hunters and prunus africana (valuable medicinal plant demanded by pharmaceutical firms) harvesters are among the important actors that have been included in the new management structure. Primary data derived from interviews and questionnaires were used to evaluate the extent to which this management mechanism meets the goal of sustainable development. The theory of New Institutional Economics (NIE) by Ostrom, which outlines eight principles that guarantee resource appropriation at the local level, was used to guide the study. The results indicate that the behavior of hunters and prunus Africana harvesters have changed in favor of conservation through collaborative law enforcement. Livelihoods have been improved as well with the introduction of incomegenerating activities (bee farming, snail farming and piggery), which have indirectly reduced the pressure exerted on natural resources. However, the study concludes that participatory governance initiatives result in fragile and conditional successes. If poverty reduction is not fully addressed, actors are unlikely to pursue the goal of sustainable development in Mount Cameroon. The theory of NIE thus provides a conditional understanding of natural resource management for sustainable development that is dependent on the wider context of development.