Although research finds high rates of risky sexual and drug related behavior among homeless young people, little research had examined how the characteristics of their social networks encourage or constrain risky behaviors. Based on a sample of 145 homeless young adults in the Midwestern United States, results revealed that having used alcohol with at least one of their network members and the presence of more conflict was associated with engaging in a greater number of sexual risk taking behaviors. Correlates of engaging in a greater number of substance use related behaviors included having older peers within the network, having used illicit drugs with at least one network member, and the presence of more conflict. The presence of a family member in one's network, however, was associated with fewer sexual and drug related risk behaviors. Overall, the social network characteristics of youth explained significant, additional variance beyond that of youth's own characteristics and their early family histories.