Tropical forests play an important role in mitigation of climate change and are the habitat for traditional and indigenous forest communities. We hypothesised that in order to improve the forest conservation by local inhabitants and to increase their revenue from the work with non-timber forest products (NTFPs), organisational, methodical as well as financial support is required. We concentrated on Brazil nuts as a profitable NTFP. After conducting field research of economic activities in two forest communities of Rondônia, Brazil, we conducted three stages of longitudinal experimental research while applying the Fair Trade concept. We organised a team of Brazil nut harvesters, developed a harvesting strategy, provided pre-financing for the stock creation of Brazil nuts and created a sales plan. Analysis of these interventions suggested that through organisational support and pre-financing, Brazil nut harvesters were able to organise themselves to increase their income and manage new forest territories sustainably. We identified the relationship between external support continuity, size of pre-financing and number of participants, their income as well as the size of managed forest territory. Clear land tenure and technical, organisational and marketing assistance are essential throughout the first years of intervention.