Health care is generally unavailable for the homeless. This heterogeneous group of men and women, including long-term street dwellers, residents of shelters, the chronically mentally ill, the economically debased, and alienated youth, are subject to a broad range of acute and chronic diseases, intensified by unsuitable living conditions, stress, and sociopathic behavior. Trauma, pulmonary tuberculosis, infestations, and peripheral vascular disease are common problems among the homeless; incomplete and fragmentary medical care permits exacerbation of chronic disorders. Outreach programs imaginatively constructed by teams of physicians, nurses, and social workers can effectively reestablish and maintain health services for these disenfranchised persons.