The thesis focuses on ‘criminal entrepreneurs,’ i.e. those individuals who behave in an entrepreneurial manner who have chosen a life of crime to obtain an income or create wealth rather than setting up and running their own legitimate businesses. The research is based on male prisoners, predominantly fraudsters and drug dealers, and was motivated by the assertion that by understanding why they have chosen this way of life it may be possible to encourage such people to use their entrepreneurial skills in a legitimate context thereby reducing recidivism. Based on an epistemological constructivist approach, the methodology used was a phenomenological one and included a moral dilemma, an ethics questionnaire and personal construct psychology linked with case studies. This is a novel approach in that it uses Kelly’s (1955) personal construct theories and repertory grid techniques in order to identify the criminal entrepreneurs’ constructs and the moral stances that they adopt when making sense of their world. The findings showed that moral reasoning theories with respect to offenders do not offer a reliable guide to moral or ethical behaviour and ignore relationships which were an important feature of the criminal entrepreneur’s life. For instance a strong bond was found to exist between some of the respondents and their parents, particularly the mother, and role models were important in their lives