Operations to counterterrorism in the southern Philippines have resulted in the arrest and incarceration of a significant number of key militants. As a result, the Philippine government has expressed concern that these inmates may radicalize others and continue to operate while incarcerated. As a preventive measure, the government has considered a number of "soft" counterstrategies, including the development of a de-radicalization program. To study the feasibility of running such a program in the Philippine corrective system, this article examines two interrelated areas of enquiry concerning how terrorist inmates are housed and whether prison gangs foster or discourage radicalization in the Philippine prison system. Initial findings suggest that the integration of terrorist inmates with prison gangs may temporarily encourage disengagement and set the foundations for de-radicalization. However, without a specifically designed intervention strategy, the terrorist inmates may revert to militancy once they have returned to their original social settings.Counterterrorism operations conducted by the Armed Forces of the Philippines (AFP) and the Philippine National Police (PNP) to dismantle militant groups in the Philippines have resulted in the arrest and detention of a significant number of individuals, many of whom are now held in the Philippine correctional system. As a result of the imprisonment of these individuals, the Philippine government is concerned that these terrorist inmates will use their time while incarcerated to radicalize others and recruit new members to join their militant cause. Addressing the radicalized intentions of terrorist inmates in the Philippine