As in all regions of Niger, the floral resource is subject to various levies by the different communities in the W Park biosphere reserve. To exploit this resource, local populations have developed a body of knowledge and techniques handed down from generation to generation. This knowledge and know-how varies according to the environment, socio-cultural considerations and plant potential of each locality. This study focuses on local people’s knowledge of the flora and techniques for processing harvested products from the Parc du W reserve. These questions are addressed through an inventory of known and used flora resources, the identification of people’s knowledge and know-how in terms of the use of flora resources and harvested products in the Parc du W biosphere reserve, and the processing techniques for harvested products. The results reveal a multiple and multifaceted use of flora in fields as varied as food, traditional pharmacopoeia, cultural practices and domestic use. Gathering appears in the biosphere as a daily practice for these populations and, depending on the context and the type of plant, ensures the survival of the local population.