We introduce the case of Ban Lak Sip, a multiethnic village located in the province of Louang Prabang in northern Laos, where various actors share concerns about the quality of agrarian lands. Villagers, local authorities, sustainable development projects and international environmental scientists all seem concerned about erosion. Since the early 1990s, the international community has joined forces with the authorities to implement rural development programs. The concept of environmental justice provides a critical perspective of sustainable development policies applied to the local management of teak plantations in Laos. It is useful to understand the consequences of these policies, their reception and appropriation, as well as their rejection or subversion by local populations. With the help of ethnographic data collected in the field, we will highlight the anthropological context of the environmental problem of land degradation in Ban Lak Sip. We will present the socio-environmental stakes formed around the disturbing development of the teak monoculture. Through the perspective of environmental justice, we will highlight the injustices suffered by villagers already victims of ethnic discrimination. These injustices are environmental, as the inequalities observed are accentuated by the soil erosion. Moreover, the public policies implemented to fight this erosion can themselves target vulnerable populations. By ignoring the capabilities of the populations concerned, they aggravate inequalities and fail to solve the problem of soil erosion.