Background: Suicide prevention is a health service priority. Homeless mental health patients present a challenge to services because of their complex health and social needs. Aims: To establish the numbers of homeless patients in contact with services who die by suicide; to describe their suicide methods and their social and clinical characteristics including aspects of clinical care. Method: A national clinical survey based on a 4-year (1996-2000) sample of people in England and Wales who died by suicide. Detailed data were collected on those who had been in contact with mental health services in the year before death. Results: A total of 131 individuals who died by suicide were reported to have been homeless at the time of death 3% of all suicides by psychiatric patients, over 30 per year. Hanging was the most common cause of death. The most frequent diagnosis was schizophrenia. Around half were in-patients at the time of death. Social and clinical risk factors for suicide were common, including drug and alcohol misuse, and recent suicidal ideas and behaviour. Despite this, their clinical care was characterised by disengagement from services as a result of missed contacts, self-discharge, lack of follow-up and lack of key worker. Conclusions: In order to reduce the number of deaths by suicide in those who are homeless and mentally ill, improvements in in-patient safety and engagement in the community are needed. This may be achieved through assertive community treatment, dual diagnosis services, and dedicated community mental health teams. © Steinkopff Verlag Darmstadt 2006.