The Tunza Junior Board typically comprises a group of ten child leaders between the ages of 10 and 12 (at the time of election). They work closely with UNEP to provide guideance on how to make UNEP processes more appealing to children, and how to sensitize children on environmental issues. The Board also helps to increase the participation of children in UNEP’s work by informing children’s groups and organizations about UNEP's activities.

The Junior Board consists of six representatives from each of the six UNEP Regions and four children from the country hosting the next Tunza International Children’s Conference. All Junior Board members are leaders and active members of an environmental organization.

The Junior Board is elected at the biennial Tunza International Children’s Conference. It has a mandate to serve for two years until the next Board is elected.