This study presents a survey of wild plants commonly used by local inhabitants in the highlands of southwest Saudi Arabia. Based upon literature review, direct observation of local inhabitants, and question-naire interviews, 36 plant species were assessed and given scores ac-cording to their use. The gaps between scientific and indigenous knowl-edge on the use of plants were estimated using a“compatibility ratio”. The score values were estimated based on seven different use categories of ecosystem services, including food, forage, medicine, wood, beekeeping, research, and education. Additional structural categories include source of materials, shade, hedges, ornamental plantings, and soil stabilization. There are discrepancies between indigenous knowledge (IK) and scien-tific knowledge (SK) but in most cases, SK of the species supports the IK and plant users preference. The results also provide information that challenges assumptions about the consistency of IK with SK. Our study highlights the importance of understanding the cultural context and uses of wild plants. Biodiversity-based knowledge holds promise for contrib-uting to sustainable use of wild plant resources and related traditions. The success of such endeavours depends on the compatibility and comple-mentarity of indigenous and scientific knowledge.