This study utilized data from the national ACCESS program (N = 7224) to investigate the prevalence of suicidal ideation and suicide attempts in a sample of homeless people with mental illness. The prevalence of suicidal ideation in this sample was high (66.2% lifetime prevalence). In addition, 51.3% of the sample reported that they had ever attempted suicide, 26.9% reported an attempt that resulted in a nonpsychiatric hospitalization, and 8% reported an attempt in the previous 30 days. Youth, substance abuse, and psychiatric symptoms were all significantly associated with suicide attempts. Those who reported a recent attempt also reported higher rates of mental health care utilization, particularly inpatient care. The authors conclude that homeless people with mental illness are at particularly high risk for suicidal behavior, however, only in part because of the high prevalence of traditional risk factors.