Drawing from primary socialization theory, we hypothesized that as Mexican-heritage youth engage in targeted parent-child communication against alcohol, they are more likely to disapprove of and consider the negative consequences of drinking alcohol. In turn, such antialcohol perceptions are likely to encourage them to intervene if a friend was to drink alcohol. The analyses were based on self-reported longitudinal data from 1,149 Mexican-heritage youth in sixth to eighth grades (M = 12 years, SD = .61). As males and females engaged in targeted parent-child communication against alcohol, they were more likely to consider the negative consequences of alcohol consumption. Consequently, they reported that they would be more likely to intervene by talking to the friend or an adult. Disapproving of alcohol consumption played a minor role for male and female Mexican-heritage youth.