The social problem of homelessness is of increasing concern to mental health professionals. In a large-scale study of homelessness in Ohio, data were collected in face-to-face interviews with 979 homeless people in 19 counties. The median length of homelessness was 60 days. Almost half the respondents cited economic factors, such as unemployment or problems paying rent, as the major reason for their homelessness. Thirty percent had been hospitalized at least once for mental health reasons, and 31 percent showed symptoms serious enough to require mental health services. Findings are also presented ir relation to a typology of the homeless—street people, shelter people, and resource people—and urban and rural respondents are compared. These and other findings support the principal conclusions that homelessness is clearly a multidimensional problem and that service strategies must reflect the multiple needs and varying characteristics of homeless people.