Designed as a companion to the Forensic Psychiatry (Oxford Specialist Handbook), Second Edition, this new cas complements the domains of both theory and practice put forward in the handbook, but also works as a standalone volume for those who wishes to enhance their decision making in cases they may confront in their discipline. Organised into three sections, the cas allows the practitioner to think through not only the technical medical aspects of real-life clinical cases, but also the legal and ethical aspects.Part A provides an introduction to the theory and practice of decision-making; Part B presents cases across clinical, legal, and ethical domains; and Part C offers frameworks for critiquing decisions.This robustly discursive approach to a fact-based but also value-laden discipline enhances the opportunity to put knowledge into practice. The Oxford Cas of Forensic Psychiatry expresses the concept that 'knowing is the only part of deciding', offering an essential practitioner's guide to decision making in clinical, forensic, and legal psychiatry.