Preventing/reducing substance use and HIV among Hispanic youth is essential to eliminating the health disparities that exist between Hispanics and other segments of the population. The objective of this article is to describe a program of research involving Familias Unidas, a Hispanic-specific, parent-centered intervention, aimed at reducing substance use and HIV health disparities among Hispanic youth. This article will focus on the theoretical foundation of the intervention, the empirical research supporting the theoretical model, the intervention model itself, the findings of the program of research, and the translation of this intervention into community practice.