This entry explores the traditional knowledge system (TKS) of the Wancho tribe in Longding district, Arunachal Pradesh, focusing on their ethnomedicinal practices. Through extensive field surveys and interviews with 150 informants as well as literature surveys, we documented the use of 25 plant species from 22 families and 17 animal species for treating a variety of health issues. The findings highlight the tribe’s deep understanding of the medicinal properties of local flora and fauna, demonstrating a sophisticated system of health care that has been transmitted orally through generations. The entry emphasizes the urgent need to preserve this invaluable traditional knowledge amid the growing inclination toward modern health care systems among younger generations. Furthermore, it emphasizes the sustainable aspects of TKS and addresses the challenges of balancing cultural health care practices with conservation efforts. This entry not only aids in preserving the Wancho’s ethnomedicinal heritage but also provides a basis for future scientific research to validate and potentially integrate these traditional practices into modern medical systems, offering alternative solutions for health care, particularly in remote areas.