This paper outlines how psychological factors related to traumatic experience and personality disorder are associated with chronic homelessness. It reports a systematic review of the literature detailing which strongly supports the conclusion that psychological disorders strongly predict homelessness and provides indicative evidence that psychological interventions can improve the life chances of homeless people. It concludes that additional research is required both to establish the most effective psychological interventions for chronic homelessness in the UK cultural context, and to evaluate the effective transfer of research knowledge from research to service delivery settings.