Agrarian reform has become at highly topical issue in Brazil and is proceeding mainly along the Amazonian pioneer fronts, thus jeopardising the continuity of forest cover. Although it is sometimes accompanied by highly proactive policies for sustainable development, the results of these policies are extremely variable. In this article, we compare four sites where agrarian reforms have been applied; they are located along the boundary between eastern Amazonia (deforestation arc) and central Amazonia (along a pioneer front) and are variously covered by sustainable development policies. In each of these sites, we surveyed plant cover, existing production systems, the characteristics of the local populations and their quality of life in the sites themselves. We bring out discrepancies between sustainable development policies applied in the sites and their environmental preservation status. These discrepancies cannot be accounted for by the characteristics of the populations and do not bear any relation to people's quality of life in the different sites. While effects of context and of local levels of acceptance account for the success or failure of sustainable development projects, the agrarian reform policies we investigated are characterized by impacts that are negative for the environment but positive for the quality of life of local populations. By proposing a series of multivariate analyses and their combination through a scalar analysis, this article also puts forward an original methodology for studies of relationships between people and their environment.