Research in the area of children's sexuality is largely based on observational and retrospective studies. Childhood studies literature increasingly calls upon the inclusion of children's voices, yet with sensitive topics ethical positions often close research possibilities in the territories of children's worlds. Children are perceived as a vulnerable group, especially when the investigation focuses on their sexual development and activity – and it is perceived that this research area is too sensitive and potentially harmful to children. Within the context of beginning a qualitative study on children's sexuality in New Zealand (including interviews with children), this paper reviews a number of studies of childhood research. These studies provide a glimpse at how research focusing on children has been conducted, and explores ethical issues arising in such research. The significance of researcher reflexivity is acknowledged for ethical research practice. The paper concludes that in research on children's sexuality a process of ethical review is limited, and that researcher competence in sensitive investigations is required. Among other difficulties for this researcher (with a professional background in child and family therapy) is the vulnerability of being a man choosing to research children.