The introduction of the participatory paradigm took place on the basis of previous changes. In Ecuador, as in other Latin American countries, the state was forced to allow non-governmental organizations (NGOs) to become involved as counterparts in conservation areas. Thus, there was a movement from the first stage, in which the state assumed exclusive responsibility, to a second stage in which NGOs began to collaborate, though still within the framework of conservation which excluded local populations. The third stage, in which NGOs adopted the local participatory paradigm, is opening the way for local organizations to become involved in planning and implementation activities. At the present time, actors formerly excluded are beginning to have a role, within the context of changes in the role of the state which, however, continues to affect the dynamics which condition conservation and development. The direction that this dynamic takes will depend on a number of factors, but there has yet to be sufficient reflection regarding this process, based on concrete experiences. At the same time, we still do not have enough specific cases, objectively and analytically documented, of community participation in the conservation of natural resources. In our opinion, what is lacking is a systematic appreciation of the methods, achievements and impacts of this type of experiences related to the social and institutional contexts in which they take place. The effectiveness of the participatory focus as it relates to the field of natural resources and biodiversity conservation remains unknown. To what extent does the participatory focus represent an improvement in the possibilities for conserving and guaranteeing appropriate management of natural resources in the long term, as compared to the traditional processes applied in previous stages? In order to begin to answer this question, we have developed a systematic study of the experiences of integrated conservation and development projects (ICDPs) which operate on the basis of the participatory paradigm in an area comprising an ecological reserve in Ecuador. Our purpose is to extract a series of lessons and establish a methodology which will permit fine-tuning in the design of participatory activities within the context of future conservation projects.