The economic downturn worldwide since 2008 has raised many issues, including an increase in homelessness. Individuals who are homeless are visible across the globe. Definitions of homelessness also vary. Living on the streets in all kinds of inclement weather, brings a different set of issues and problems including physical and mental illnesses. Here homelessness is defined as a lack of customary regular access to a conventional dwelling unit. It has been shown in several studies that nearly half were either depressed or had substance use disorders and half had traumatic brain injury. Homelessness is a social issue and the role of the psychiatrist in reaching these vulnerable individuals is a matter of critical importance. In the UK health services are geographically delineated making it more difficult for ‘out of area’ individuals to get help. The responsibility for looking after people who are homeless, have mental illness or physical co-morbidity, lies with policymakers as well. As clinicians we must advocate for vulnerable patients and psychiatry care needs to be in a joined-up manner. Early interventions and home treatments where and if available are suitable and can be effective but are often linked with secure addresses. Policies must take into account huge variations across cultures and societies and the contributions that unemployment and poverty can play in increasing homelessness. Whether psychiatric disorders lead to homelessness and whether homelessness leads to mental illness is a circular argument and this vicious downward spiral needs to be broken by adequate care and policy support.