Abstract: Introduction Traditional herbal medicines are naturally occurring, plant-derived substances with minimal or no industrial processing that have been used to treat illness within local or regional healing practices Traditional herbal medicines are getting significant attention in global health debates In China, traditional herbal medicine played a prominent role in the strategy to contain and treat severe acute respiratory syndrome (SARS) (1) Eighty per cent of African populations use some form of traditional herbal medicine, (2,3) and the worldwide annual market for these products approaches US$ 60 billion (2) Many hope traditional herbal medicine research will play a critical role in global health China, India, Nigeria, the United States of America (USA) and WHO have all made substantial research investments in traditional herbal medicines (2) Industry has also invested millions of US dollars looking for promising medicinal herbs and novel chemical compounds (4,5) This is still a relatively modest investment compared to the overall pharmaceutical industry; however, it raises interesting ethical questions, some of which are not faced in more conventional drug development As attention and public funding for international traditional herbal medicine research collaborations grows, more detailed analysis of ethical issues in this research is warranted Scant literature has addressed selected issues such as informed consent and independent review related to traditional herbal medicine research (6,7) Here we apply a practical, comprehensive and widely accepted ethical framework to international traditional herbal medicine research (80 We examine in detail difficult questions related to social value, scientific validity and favourable risk--benefit ratio We conclude with implications for future research in this area, focusing on the importance of collaborative partnership Case A government agency from a developed country is conducting an HIV-treatment trial in Africa A traditional herbal medicine, Africa Flower, has been used for decades to treat wasting symptoms associated with HIV Local traditional medicine healers believe Africa Flower is an effective antiviral It is already widely used for immune boosting in AIDS In vitro pharmacokinetic studies suggest potential interference with vaccines, and animal models show liver toxicity at very high doses There are no systemic side-effects reported for humans in the literature A few case series have shown mixed results Local leaders are requesting the government agency conduct a large, randomized controlled trial (RCT) of Africa Flower to test its efficacy as a novel adjunctive therapy to slow progression to MDS Ethical framework Cases like these present challenging questions related to the role of traditional herbal medicines in public health In general, international research on traditional herbal medicines should be subject to the same ethical requirements as all research related to human subjects (9) An ethical framework previously outlined by Emanuel et al and revised for international research (8) offers a useful starting point for thinking about the ethics of international traditional herbal medicine research This framework includes eight ethical requirements for clinical research (Table 1) (8) These ethical requirements are universal and comprehensive but must be adapted to the particular social context in which the research is implemented (8) Of these, fair subject selection, independent review, informed consent, and respect for enrolled subjects have been discussed previously in the literature on the ethics of global health research and raise few issues unique to international traditional herbal medicine research (8) However, social value, scientific validity, and favourable risk--benefit ratio raise specific challenges in international herbal medicine research that have not been adequately discussed …