Identifying and addressing ethical issues are key to the success of any clinical trials, particularly when working with vulnerable populations. Dr Phaik Yeong Cheah leads the Department of Bioethics & Engagement at the Mahidol Oxford Tropical Medicine Research Unit (MORU) in Thailand. She is particularly interested in ethical issues in community engagement, data sharing, consent and assent in paediatric research. Creative Commons Attribution-Non-Commercial-Share Alike 2.0 UK: England & Wales; http://creativecommons.org/licenses/by-nc-sa/2.0/uk/