This article presents family-level results from an ongoing study examining the impact of the CHAMP (Chicago HIV prevention and Adolescent Mental health Project) Family Program, a family-based HIV preventative intervention meant to reduce the amount of time spent in situations of sexual possibility and delay initiation of sexual activity for urban youth in the 4th and 5th grades living in neighborhoods with high rates of HIV infection. The CHAMP Family Program has been developed, delivered, and overseen by a collaborative partnership, consisting of community parents, school staff, community-based agency representatives, and university-based researchers. Design of the program was informed by input from this collaborative partnership, child developmental theory of sexual risk, and empirical data gathered from the targeted community. This article presents findings that suggest CHAMP Family Program impact on family communication, family decision-making, and family-level influences hypothesized to be related to later adolescent HIV risk. Implications for future family-based HIV prevention research are discussed here.