Recognising the importance of plants in traditional healthcare and traditional healers, this article examines the claim that Traditional Knowledge (TK) is critically relevant to the human quest for sustainable living. Concepts of TK, traditional, complementary and/or alternative medicine and modern health are examined to show links between the three and contributions of TK to various sectors of modern health in Malaysia, particularly in Sabah. It then looks briefly at loss of TK, ways and means of reviving or maintaining TK while still securing the integrity of TK holders. The article acknowledges the urgent need to document valuable knowledge in view of rapid depletion of forest habitats, native healers with TK often fail to transfer their knowledge to younger generation, and due to easier accessibility of modern health facility younger people are not compelled to inherit the TK of their forefathers. This article does not deal with protection of TK.