Medicinal plants remain vital in the Phu Tai community in Amnat Charoen in Thailand. Traditional healers' knowledge is largely undocumented in the literature. Our objective was to document their medicinal plant practices to preserve this valuable knowledge. Our informants were 15 Phu Tai healers. We calculated use values (UV), family importance values (FIV), and informant agreement ratios (IAR) to gauge the significance of the 211 medicinal plants used by the healers. The most important plant families were Fabaceae and Zingiberaceae (FIV = 93). Kha min () was the most important medicinal species (UV = 0.66). The decoction was the most common preparation method (85%). Skin/subcutaneous cellular tissue disorders had the highest informant agreement ratio (IAR = 0.73). Shrubs were the most common life form (36%) among the medicinal plants; the majority were collected from community forests (51%) and were native to Thailand (86%). The most frequently used plant part for medicine was the leaf (27%). Medicinal plants that can be purchased were Ueang mai na (), Thep tharo (), and Som khon (). Interestingly, monks served as traditional healers. The healer's age and education were not correlated with the number of medicinal plants they knew. The Amnat Charoen healers possess a rich traditional knowledge of medicinal plants. The information reported here is invaluable for further research in the field of cross-cultural ethnobotany and ethnopharmacology.