In November 2016, the Council for International Organizations of Medical Sciences published its revised International Ethical Guidelines for Health-related Research Involving Humans. In relation to earlier versions, the scope of the new guidelines has been expanded to include public-health research. While successful to some extent, the document does not take into sufficient account the differences between public-health research and other types of health research. It is silent on some issues of importance to public-health research, such as its definition, health inequities (...) and novel research methodologies. Its treatment of some other issues, including the need for researchethics committee approval, consent, community involvement and dissemination of research results, are deficient in some respects. The guidelines that are particularly applicable to and useful for public-health research deal with social value, the health needs of communities and populations, community engagement, disasters and disease outbreaks, cluster randomised trials and data sharing. Much further development of the foundations and applications of public-health research ethics is needed to inform future revisions of the guidelines and of other international and national research-ethics documents. (shrink)