The Mamirauá Sustainable Development Reserve is situated in North Western Brazil, in the upper reaches of the Amazon, at the confluence of the Solimões and Japurá Rivers. It is located within an area of flooded forest, or várzea, and is of exceptionally high global and local biodiversity value. There are many endemics, and plant diversity is high. The fishery with around 400 recorded species makes it one of the most diverse in the world. About 1800 local people live within and around the reserve depending on fish, some agriculture and timber extraction. In the 1980s, a team of Brazilian scientists started some innovative biological and anthropological research in Mamirauá. The area at the time was classed as an Ecological Station – one of the strictest protected area categories in Brazil, which allowed no human habitation and no harvesting. Out of the scientists research grew recognition that without involving local people in the management of the area, its long-term viability would be threatened. The intense pressure on the area from external commercial interests, coupled with the lack of state government resources for surveillance meant that effective enforcement by state authorities was near impossible. A new concept was developed – a protected area that would allow for human habitation and sustainable use of the local resources. Returns from harvesting would then provide local people with the incentive to engage in surveillance and conservation activities. The scientists lobbied the Brazilian Government hard, and eventually a new category – a Sustainable Development Reserve – was created with Mamirauá designated as such in 1996. The scientists formed an NGO through which they carried out further work in the area – for which they received substantial grants from a number of donors. Subsequent work in the MSDR focused on developing suitable approaches for carrying out effective conservation in an area of high global and local biodiversity value, whilst at the same time improving the livelihoods of the residents and legitimate users of the area. The SCM’s core aim was to establish a working model, which could then be used to demonstrate ‘people in protected areas’ approaches so that these could be replicated on a much wider basis in similar Amazonian ecosystems. It is for this reason that after ten years of its support, DFID commissioned this study, with a view to ensuring the key lessons of the Mamirauá project gain wide readership and understanding, not only in Brazil but also elsewhere. There were also several lessons learnt from how to manage projects and donor interactions. These have also been captured.