This study examined health and related issues in the adult homeless population of Dublin. The data was collected over a five day period by trained interviewers using an anonymous questionnaire. The response rate was 64%. The population was made up of different demographic sub-groups. Almost 80% were smokers, 30% drank alcohol beyond recommended limits and 30% used illegal drugs. Almost half perceived their health as poor. Sixty six per cent of people had at least one physical or psychiatric problem. Chronic disease was reported by 41%. Health problems varied with demographic and behavioural factors. Utilisation of services varied with age, sex and other demographic factors. Many barriers to service utilisation were identified. Homeless people have increased risks for illness and suffer similar, but more prevalent, health problems to the general population for which they do not always receive adequate or appropriate care. Recommendations include further research and specific service developments.