The role of the family in the radicalisation and de-radicalisation process has received little research attention. Previous research has neglected the use of criminological theory in examining this role. I aimed to fill this gap in the literature. In this thesis, I conducted a deductive qualitative analysis of the autobiographical accounts of 14 terrorists to examine the extent to which their perceptions of the role of family in the radicalisation and de-radicalisation process aligned with criminological theory. The findings support the applicability of social learning theory, general strain theory and social control theory in explaining the role of the family in radicalisation. The findings also support the applicability of the age-graded theory of social control in explaining the role of the family in de-radicalisation. These findings contribute to the existing literature on the role of family in the radicalisation and de-radicalisation process, and also build upon previous studies that highlight the utility of criminological theory in explaining radicalisation and terrorism.