Clear rights over resources and locally legitimised tenure regimes for managing natural resources are essential for good governance in forest areas. External efforts to change local development conditions and the goals of natural resource-dependent communities — be they attempts to link them to commodity markets as a poverty alleviation strategy, schemes for environmental services rewards, or participation in international treaties to mitigate climate change, must build upon this level of collective action and social legitimacy to be successful. Internationally promoted conservation efforts face similar challenges.<br /> <br /> More often than not, conservation and community interests in tropical forests run a path of dispute, sometimes conflict and negotiation, and seldom, a successful reconciliation of differing proposals for forest resource protection, ownership, and use. However, there are cases where the expansion of forest areas under conservation has gone hand-in-hand with an increase in community tenure and access rights. This is possible when there is a process of negotiation and social legitimisation of a working model of shared rights and responsibilities over resources, which leads to a land-use pattern that contributes to the dual goals of improved human well-being and forest conservation.<br /> <br /> This paper presents the history, evolution, and initial outcomes of the joint effort to establish the Mayan Biosphere Reserve and the community forest concessions in the Department of Petén, Guatemala. Then it lays out some of the challenges emerging from initial success. The paper argues that initially antagonistic proposals for conservation and livelihood interests from these highly biodiverse forests — the first externally induced and the latter local practice—were only able to be achieved by developing complementary tenure and land-use regimes, each incorporating goals of the other and legitimized by all participating parties. Through a deliberative, sometimes confrontational process, conservation and livelihood interests battled until a workable solution was found. At the heart of the solution is an approach to community-based forestry. The paper highlights the initial conditions and contradictions that led to the proposal of community forestry concessions, gives an overview of how these shaped the resulting tenure and rights regimes, and lays out the challenges now emerging from its initial success.