The Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) came into effect in 1975 to protect certain species of wild fauna and flora against overexploitation through international trade. Determining which trade is detrimental to the survival of species in the wild can be a major difficulty in the implementation of CITES by national authorities, partly due to limited knowledge and understanding of the species’ biology, management, and the impacts of harvesting. Some of this knowledge could be acquired through targeted scientific research. However, to date there exists no general overview of the current use of biological information in determining detriment in CITES to help scientists identify research priorities. For an international meeting in 2008, over 100 scientists and regulators compiled 60 case studies covering a wide range of CITES-listed taxa, outlining how information on the biology, harvesting and management might be used to determine whether international trade is detrimental. We used these case studies, workshop conclusions, and other published literature, to identify ten potential research directions for the scientific community which, if addressed, could greatly assist in the making of non-detriment findings. We hope that this will encourage more scientists to study CITES-listed species, and foster more collaboration between research scientists, CITES national authorities, CITES technical committees and local communities. The case studies highlight a general need for advice on how to identify and manage levels of risk involved when assessing possible detriment, and for advice on assessing detriment under complex harvesting scenarios such as when multiple species, or parts of individuals, are harvested. Broadly, they highlight an opportunity for scientists to further develop a body of scientific studies that propose, refine and adapt methods for assessing detrimental trade in CITES-listed taxa. Comparisons within life-form groups indicated the potential for the identification of practical advice that could apply to groups of taxa. The case studies highlighted a widespread need for more information gathering studies of CITES-listed taxa such as the broader impacts of harvesting on populations and ecosystems, and the potential long-term evolutionary impacts. The case studies also highlighted the need for practical advice on how to implement adaptive management programmes and for research into enterprises based on the harvesting of CITES-listed species from the wild.