Mass media campaigns have been designed to counter a rise in e-cigarette use among young people. No studies to date have established pathways from campaign exposure to e-cigarette use behaviors. This study examines the mechanisms through which exposure to the truth® campaign may prevent the progression of e-cigarette use among youth and young adults. Data included four waves of the truth longitudinal cohort, a probability-based, nationally representative survey: Wave 1: September 2020-March 2021; Wave 2: July-October 2021; Wave 3: January-May 2022; and Wave 4: October 2022-January 2023. The sample (N = 4,744) was aged 15-24 years and nicotine naive at Wave 1. Latent growth structural equation modeling techniques examined the pathway from cumulative frequency of ad exposure (CFE) to the e-cigarette use progression via campaign-targeted attitudes. The direct effect from CFE to e-cigarette use progression was not significant. The overall indirect pathway shows that CFE was significantly associated with lower progression of e-cigarette use (β = -.01, p < .0001). CFE had a significant positive association with each campaign-targeted attitude, and each attitude was significantly associated with stronger perceived norms against e-cigarette use. Stronger perceived norms were significantly associated with a slower progression to e-cigarette use (β = -.21, p < .0001). Awareness of the truth antivaping campaign follows a pathway of targeted attitudes and perceptions of acceptability, then to slowed progression toward initiation of e-cigarette use. Antivaping campaigns should focus on shifting perceptions of acceptability to reduce e-cigarette use among young people. (PsycInfo Database Record (c) 2024 APA, all rights reserved).