Researching the ‘experiences’ of people who have been sexually abused as children or who have themselves committed sexually abusive  acts  raises a range of methodological and ethical dilemmas. In the past, researchers have often relied on retrospective research designs, with the majority of studies of child sexual abuse undertaken with adults who are asked to recall their childhood experiences of abuse. However, there are compelling reasons to involve children in research in order to hear their voices and experiences directly. At the same time, the complex dynamics inherent in child sexual abuse and sexual exploitation pose specific practical and ethical challenges to researchers wishing to undertake research in this area. Key issues that are  addressed in this chapter are: the benefits of involving children who have been affected by sexual abuse in research, choosing ethically and developmentally sensitive methodologies, the gender and power of researchers, confidentiality and informed consent, safety and protection of research participants, and managing distress and disclosures.