This paper uses a case study approach to explore issues for mental health nurses in relating with suicidal patients. The phenomenon of 'malignant alienation' is described, whereby the suicidal tendencies of some mentally ill patients are thought to be exacerbated by negative attitudes and interactions with staff and other patients. The study seeks to establish whether such a process can occur with regard to mental health nurses, to explore the process in detail and to identify causative and preventive factors. Case study methodology is used to answer the research questions. The rationale for this methodology is explained. A case study is then presented, demonstrating, first, that the process of malignant alienation can indeed occur as a result of interaction between nurses and a patient whose behaviour they find challenging and, second, that a more positive approach by nurses to the same patient can have therapeutic outcomes.