De-radicalization among young people is a crucial fight of national and international terrorism globally. It is one of the post-terrorism security intervention strategies that is thought to address the root causes of youth engagement in terror activities. The study investigated the influence of de-radicalization as a post-terrorism security intervention strategy on social relations in the County Government of Nairobi, Kenya. The study adopted a mixed methods research design. It also used a sample size of 384 respondents, comprising 361 were heads of households, 15 members of Nairobi County Security Board and 8 survivors of terrorism acts. Convenient sampling technique was used to select heads of the households, purposive sampling techniques to identify members of Nairobi County Security Board and snowball sampling used to identify terror survivors. Key informants interview schedule as well as interview schedule were essentially employed methods of data collection. The data collected was subsequently analysed using both qualitative and quantitative methods, that is, descriptive statistics mainly used for qualitative data and direct quotation used for qualitative data. From the results of the study, the Kenyan youth deradicalization programmes play a significant role in transformation of youth to be productive members of the society and eliminate terror mind-set. It was reported that youths have proved more