In phytopharmacy, the term 'traditional use' is widely found in colloquial language but has also great significance for registration procedures of medicinal products. It is therefore justified to explore its actual meaning from the perspective of social and pharmaceutical history. It is shown that a tradition is founded by transmission of knowledge and techniques over at least three generations, while the life span of a generation may vary widely. Changes and adaptations to technical advancements do not at all avoid but even constitute the development of traditions. Historical research provides valuable knowledge about effectiveness and risk of phytopharmaceuticals. Criteria of traditional use may complement but not substitute modern evidence based methods; however they always need to be applied historically sound. Copyright © 2012 S. Karger AG, Basel.