Morbid jealousy is encountered in general, old age and forensic psychiatry, and clinicians in each specialty should be familiar with its recognition and management. As well as clinical matters, the issue of risk to the patient and others is prominent in the consideration of morbid jealousy. Hospitalisation is sometimes required, the use of compulsory admission is not infrequent and treatment in secure settings is occasionally warranted. This review addresses the nature of morbid jealousy, its psychopathology, diagnostic issues, associations, risks and management.