This study was carried out with three goals: (1) to determine the prevalence of suicidal ideation and suicide attempts among the homeless; (2) to determine what aspects of homelessness predict suicidality, and (3) to determine which aspects remain predictive after controlling for key covariates, such as mental illness. A sample of 330 homeless adults were interviewed. Sixty-one percent of the study sample reported suicidal ideation and 34% had attempted suicide. Fifty-six percent of the men and 78% of the women reported prior suicidal ideation, while 28 percent of the men and 57% of the women had attempted suicide. Childhood homelessness of at least 1 week without family members and periods of homelessness longer than 6 months were found to be associated with suicidal ideation. Psychiatric diagnoses were also associated with suicidality in this sample.