This is a book chapter in which approaches to risk assessment and management in the domains of mental health and criminal justice are set out and discussed. The chapter is particularly concerned with practice with ‘mentally disordered offenders’. Psychiatric and criminal justice approaches are compared and contrasted and ‘clinical’, ‘actuarial’ and ‘anamnestic’ methods of risk assessment are reviewed. The paper tries to strengthen the links between risk assessment and risk management, canvases the opportunities and challenges of inter-agency work and urges a clearer connection between the debates around risk management and compliance.