The number of homeless persons and their characteristics has changed markedly in recent years. Evidence from studies in the 1980s projects a profile of problems and needs among this new homeless population that complicates efforts at providing social and medical services. This paper presents a descriptive profile of the backgrounds and health problems of homeless persons in Boston and analyzes variation in length of homelessness and frequency of use of a shelter for the homeless. Implications are drawn for service delivery policies. The analysis is based on a random sample of 500 intake records from the second largest homeless shelter in Boston.