Ethnomedicinal study of medicinal plants was conducted to document the indigenous plant based medical knowledge of people in Tehsil Loi Mamund, Bajaur Agency, Pakistan. A total 160 informants were selected to collect the information on medicinal plant use from the study area.  Data were collected using semi-structured questionnaires and interviews, field observations and group discussions. Informant consensus factor (ICF) and fidelity level were calculated to assess the agreement of informants on the medicinal value of plants. The introduced plants were collected post interviews and later on pressed on herbarium serial number for reference. Afterwards, the data were analyzed through relative frequency of citation (RFC) Use value (UV) in total, 75 medicinal plant species were use by the local community for treatment of various diseases in the study area. Among the total medicinal plants species, In the study area the ethno-medicinal value of Opuntia littoralis (Engelm.) Cockerell and Viola indica W.Beckerwas reported for the first time which has moderate confidential level in terms of their medicinal uses in the study area. Important ethno-medicinal plants of the area with high UV are Berberis lyceum Royle (0.94), Viola indica (0.90), Isodon rugosus (Wall. ex Benth.) Codd (0.88), Foeniculum vulgare Mill.(0.87), Peganum harmala L (0.86), Solanum virginianum L. (0.85), and Cassia fistula L. (0.79). Medicinal plants with higher RFC values are Calotropis procera (Aiton) Dryand. (0.86), Cannabis sativa L. (0.82), Mentha piperita L. (0.82), Mentha longifolia (L.) Huds.(0.76), Allium sativum L. (0.73), Coriandrum sativum L. (0.73), and Foeniculum. vulgare (0.72). Disease categories such as ear problems, eye disease, tooth ache, head ache; problems of sensory system, evil eye, evil spirit; anemia and malaria had higher problems of respiratory system ICF values, suggesting high incidence of these diseases in the study area and agreement of people on their remedies. Agricultural expansion, firewood collection, and use of plants for construction were reported as major threats to plants of the study area. In order to protect biodiversity erosion and loss of indigenous knowledge, local communities must be taught and involved in conservation and management of plant resources and their indigenous knowledge.

Index-term: Ethnobotany, Informant Consensus Factor, Medicinal plants