The present study considered risk factors associated with suicidal ideation and the likelihood of a suicide attempt in a sample of 297 homeless and runaway youth from four Midwestern states. It was hypothesized that sociodemographic characteristics, family factors, suicide exposure, street factors, externalizing behavior, and internalizing behavior would be related to suicidal ideation and to the likelihood of a suicide attempt. It was also hypothesized that suicidal ideation would mediate the relationship between the other predictor variables and the likelihood of a suicide attempt. Over half the sample (53.9%) endorsed some level of suicidal ideation, and over one quarter (26.3%) attempted suicide in the year prior to the interview. Univariate and multivariate results indicated that sexual abuse by a family member, knowing a friend who attempted suicide, drug abuse, and internalization were highly related to suicidal ideation. In the absence of suicidal ideation, sexual abuse, sexual victimization while on their own, and internalization were highly related to the likelihood of a suicide attempt. Finally, the hypothesized mediating effect was found for both sexual abuse and internalization. (Authors)