The UK funds an increasing amount of biomedical research in developing countries. Research proposals are reviewed by research ethics committees, usually in both the UK and the countries where research is to take place. Exact ethical requirements vary according to national policy, funding body and research institution. A key international document on research ethics, the Declaration of Helsinki, will be revised in 2008. This POSTnote describes the types of research conducted in developing countries, the ethical review process and the arising issues.