I N MAURITANIA, herbal medicine is an integral part of the culture of the society. However, ethno-medicinal data remain scarce and fragmentary. In this work, the ethno-medicinal knowledge in five regions inhabited mainly by two Mauritanian ethnic groups: the "Maures" and the "Peulhs" was explored. These regions present the climatic stages of the country from hyper-arid to SaheloSaharan. This suggests that the use of plants by the population in their health care will depend on their presence in the environment. Our methodology consists of a diagnosis of the current situation of this herbal medicine through an ethno-medical survey of healers in the regions of Tiris Zemmour, Inchiri, Adrar (North), Trarza and Brakna (South West). seventy-six informants were enrolled in this study. Results showed that (93.42%) of the informants belong to the 'Maures' community and that women (64.45%) are more involved in this practice The majority of traditional healers are married (97.38%). The older people and the least educated are the most present in the profession. The ethnobotanical study made it possible to inventory 56 medicinal species, used in phytotherapy, belonging to 25 families. The most cited are Ziziphus lotus, Ziziphus mauritiana, Vachellia tortilis, Adansonia digitata, Gymnosporia senegalensis, and Senegalia senegal. The modes of administration exhibit that the aerial part is the most used (53.50%). The majority of remedies are prepared as infusions (48%) and maceration (22%). The majority of medicines are administered orally (99.77%). Most of medicinal species in the five regions studied are prescribed for diseases of the digestive tract (53.50%). No difference has been observed in the use of this medicine among ethnic groups. these data will serve as a basis for researchers and as a reference for establishing action plans for the conservation of Mauritanian flora in general and traditional medicine in particular.