Islamism in the modern world is clearly portrayed as a notion of religious extremism. Bangladesh on the other hand as a young developing nation finds its root into two different branches of ideology: Bengali cultural and Muslim ideology. The militant groups in Bangladesh have been found active recently specially after 2015 when international media spotted Al Qaeda in the Indian Subcontinent (AQIS) and the Islamic State’s (IS) presence in the country. This study, however, aims at understanding the Islamic radicalisation in Bangladesh through the analysis of Islamist political and non-political groups’ functions and propaganda. In this article the ideas of Islamic radicalisation, mutations and role and function of Islamist militant as well as political group have been discussed. The role of Jamaat-e-Islami and its student wing in the radicalisation have been discussed. The disputed relationship of Jamaat and the radical extremists as well as ban on their politics have created a complex scenario in Bangladesh. The political polarisation and politicising of counter terrorism effort have weakened the government’s effort to tackle radical organisation. Honest and tolerant political intervention by welcoming different views regarding the solution of the radicalisation problem can help address it effectively.