This paper describes a model of flexible psychiatric outreach service in Canada designed to meet the needs of persons who are homeless or marginally housed and have mental illness. The activities of the Psychiatric Outreach Team of the Royal Ottawa Hospital for individual clients and the community agencies who serve them are profiled, followed by a demographic and mental and physical health profile of the clients seen in the past year. The differences from other models of service and the benefits and limitations of this unique multidisciplinary team are discussed, with implications for future service development for this vulnerable population. (PsycINFO Database Record (c) 2007 APA, all rights reserved) (journal abstract)