The article presents the process and the outcomes of child participatory action research (PAR) conducted in Bosnia and Herzegovina (BiH), as part of UNICEF activities in this country. The study was implemented through children acting as co-researchers, organised in so-called Children's PAR Groups, initiated in three BiH municipalities. Children collaborated with a Support Group in each of the municipalities, comprised of adults who helped children implement their activities. Children chose to focus their research on community participation and ensured a number of outcomes in a relatively brief period. The value of PAR in the development of child participation was highlighted by children and adults who took part in the study. Prejudices that children have toward adults, and vice versa, were issues identified as main barriers for wider children's participation. This article also reviews a number of ethical challenges highlighted in the study, such as the organisational barriers to children's participation and project-based support for its development.