Introduction. Alcohol consumption, including heavy drinking, is the fourth leading preventable cause of death in the United States. Youth who engage in heavy drinking are likely to experience a number of problems associated with their use. In 2015, U.S. prevalence of heavy drinking was 17% among 12th graders. These data suggest a clear need for conducting alcohol prevention activities among youth. Method. We designed the Click City®: Alcohol program for 7th graders, with a booster in 8th grade. We conducted an efficacy trial in 25 schools in three counties in Oregon. Schools were randomized to either the Click City: Alcohol (n = 12) or Usual Curriculum condition (n = 13). We present the results of a short-term evaluation, assessing change in outcomes from baseline to 1 week following the intervention among students in Click City: Alcohol schools versus those in Usual Curriculum schools. Results. Students who used the Click City: Alcohol program significantly decreased their intentions to drink heavily in the future, as compared with students in the Usual Curriculum control condition, although the effect size was small. Changes in the targeted mechanisms were in the expected direction and were significant for all but one mechanism, with moderate effect sizes. Conclusion. Our short-term findings provide preliminary support for the efficacy of the Click City: Alcohol program to change adolescents’ intentions to engage in heavy drinking. If the results are maintained over time, the program has the potential to prevent the onset of heavy drinking among teens and reduce the negative consequences associated with heavy drinking, including neurological and other health consequences.