This paper reflects on some of the ethical challenges encountered by the authors whilst undertaking sensitive qualitative research with parents and children who are traditionally hard to reach. The research aimed to provide more holistic and in-depth accounts of parenting on a low income in diverse social circumstances than already exist. The nature of the sample and the subject matter that was covered inevitably raised many familiar ethical dilemmas and some that are less often encountered in practice, particularly in relation to child protection. In this article we discuss our approach to ethics, some of the ethical challenges we encountered undertaking work with families and discuss the complexity of decision-making around risk of harm to children. We conclude that a clear framework to avoid harm should be developed at the outset and a transparent approach to child protection issues should be used. Additional time and resources need to be incorporated at the planning stage of similar projects in order to develop appropriate methods, ensure effective decision-making and support researchers.