A study of risk factors for homelessness among the severely mentally ill was extended to include women, and a case-control study of 100 indigent women with schizophrenia meeting criteria for literal homelessness and 100 such women with no history of homelessness was conducted. Subjects were recruited from shelters, clinics, and inpatient psychiatric programs in New York City. Clinical interviewers used standardized research instruments to probe three domains of risk factors: severity of mental illness, family background, and prior mental health service use. Findings adjusted for ethnicity revealed that homeless women had higher rates of a concurrent diagnosis of alcohol abuse, drug abuse, and antisocial personality disorder. Homeless women also had less adequate family support.