Objective: To test the hypothesis that changes in alcohol-related attitudes and expectancies mediate the effect of alcohol advertising on youth drinking.

Design: Longitudinal survey with a 9-month interval.

Setting: Twenty-nine public schools in 3 German states.

Participants: A total of 2130 sixth- to eighth-grade students (age range, 11-17 years; mean, 12.2 years) who were nondrinkers at baseline.

Main exposures: Exposure to alcohol and nonalcohol advertising was measured at baseline with masked images of 17 commercial advertisements with all brand information digitally removed; students indicated contact frequency and brand names.

Outcome measures: Positive attitudes toward alcohol, current alcohol use, lifetime binge drinking.

Results: A total of 581 of the students (28%) started to drink alcohol during the observation period. Alcohol use initiation was positively related to baseline alcohol advertisement exposure. This effect of alcohol advertisement exposure on alcohol use was partially mediated by a change in alcohol-related attitudes, which explained about 35% of the total effect after controlling for baseline covariates and exposure to other advertising contents. The analysis revealed similar results for binge-drinking initiation.

Conclusion: More favorable attitudes about alcohol may be one path through which alcohol advertising exerts behavioral influence.