The link between occupational performance, mental health and offending behaviour is increasingly being recognized. Consequently the number of occupational therapists working with mentally disordered offenders is rising. This text has been written by forensic occupational therapists practising in the UK. It describes their experience of working within a range of environments, including maximum security prisons and the community. It also addresses practice in specialist clinical areas, including learning disabilities, women's services, self-injury, addictive behaviour and psychopathy. It is a first step in outlining occupational therapy principles and practice within a multidisciplinary framework and should be beneficial to all occupational therapists working in forensic settings as well as other team members wanting a better understanding of occupational therapy.