The rationale for targeted and tailored substance use prevention programs derives from essentially three observations: 1) differences in substance use prevalence rates across racial/ethnic groups; 2) differences in the prevalence of the risk factors for substance use across racial/ethnic groups; and 3) differences in the predictors of substance use across groups. This article provides a model for understanding cultural sensitivity as it pertains to substance use prevention. Cultural sensitivity is defined by two dimensions, surface and deep structure. Surface structure involves matching intervention materials and messages to observable, "superficial" characteristics of a target population. This may involve using people, places, language, product brands, music, food, locations, and clothing familiar to, and preferred by, the target audience. Surface structure refers to how well interventions fit within a specific culture. Deep structure involves incorporating the cultural, social, historical, environmental, and psychologic forces that influence the target health behavior in the proposed target population. For example, peer influences may exert a greater influence on substance use initiation among White and Hispanic than among African