This article explores children's participation in research, from the perspectives of researchers who have conducted research with children. Researchers' reports, gained using an email interviewing method, suggest that children's participation rights are particularly compromised when the potential child participants are considered vulnerable and the topic of the research is regarded as sensitive. Such perceptions result in stringent gatekeeping procedures that prevent some children from participating in research. This article concludes that children should be viewed, not as vulnerable passive victims, but as social actors who can play a part in the decision to participate in research. Such a view would result in more careful attention to communicating effectively with children about research, and ensuring that they may have a more central role in decision-making about participation.