In parts of the Republic of Iraq and the Syrian Arab Republic controlled by the Islamic State children were subjected to systematic indoctrination into extremist ideologies, with many of them being actively integrated into the Islamic State to be trained as the next generation of fighters. As Islamic State lost virtually all physical territory to other actors in the region, these children will present a serious long-term threat to security and stability unless successfully reintegrated into functioning communities. When available data on the way the Islamic State recruited, trained and indoctrinated children is examined, it can be seen that these children exhibit characteristics of child soldiers as well as those usually found in members of terrorist organizations. This paper therefore argues that, in order to devise and implement an optimal approach to their reintegration, relevant lessons should be drawn both from child soldier reintegration initiatives as well as from terrorist deradicalization and rehabilitation programs. Those lessons should then be adapted to specific requirements and constraints of this particular case.