This study draws upon eld research on former members of the Indonesia Islamic State (NII), Fajar Nusantara Movement (Gafatar), and deportees and returnees of the Islamic State of Iraq and Syria (ISIS). The NII group under study is speci cally that of the former NII KW9, a group believed to be led by Panji Gumilang who also ran Al Zaytun, a large Islamic Boarding School (pesantren) in Indramayu. The former Gafatar activists studied here are those who received rehabilitation programs from the government after being forcibly evicted from West Kalimantan for being declared dangerous and perverted. Meanwhile, the ISIS group members here are those who had aspired to join as well as those who had joined the organisation. The research used qualitative methods by conducting structured interviews and literature reviews. The focus emphasized on how they got involved in the rst place and how they got out of the groups. The number of respondents interviewed was 46 people, comprising 20 ex- NII, 16 ex-Gafatarians, and 10 families of ISIS deportees and returnees. This study was conducted from August 2017 to February 2018. The finding shows the importance of two important aspects in assessing a group by using an initial assessment among people who are disappointed by the group then decided to leave the group and the people who have not expressed disappointment so that they still believe in the ideology of the group. Of the two aspects above, the easier and more important to deradicalize by the intervention program is the people in the first aspect who have experienced the process of disappointment in the group. People who have not felt the process of disappointment need to have another approach before entering the deradicalization program- -excepting Gafatar.