All psychological and social research presents ethical dilemmas, many of which centre around the difficulties which flow from the power imbalances between those conducting the research and the research respondents or participants. Issues of power are magnified in research undertaken in contexts of poverty, and there is a burgeoning literature on ethical issues in research in developing countries. In this article, we augment the existing literature by focusing on the experiences of an assessor working in a controlled trial of a mother-infant intervention in a poor South African community. We consider issues of community expectations, the presentation to our project of physical health problems, the issue of HIV/AIDS, cultural beliefs which impact on the research, child protection issues, and the tensions between research assessment and ubuntu--a cultural norm which requires helpful engagement with others. We suggest that our experiences may assist with the development of further research.