Background Unacceptably high levels of e-cigarette use among youth paired with growing research about the dangers of vaping demonstrate a critical need to develop interventions that educate young people to reject e-cigarette use and promote cessation for current users. Vaping: Know the Truth (VKT) is a free digital learning experience prioritizing middle and high school students that aims to improve students’ knowledge about the dangers of using e-cigarettes and provide quitting resources for those who already vape. The current study was designed to evaluate whether students receiving the curriculum increased knowledge of the dangers of vaping. Methods The outcome measures were calculated as the change in the number of correct responses from the pre- to post-module assessments among middle and high school students who completed four modules of the VKT curriculum ( N = 103,522). Linear regression was performed to determine the association between the student’s pre-module assessment score and the knowledge change score after completion of the four modules. Results Students’ e-cigarette knowledge significantly improved by an average of 3.24 points ( SD = 3.54), following implementation of the VKT curriculum. This indicates that participants answered more than 3 additional questions correctly, on average, after the intervention. Conclusion Findings demonstrate that the Vaping: Know the Truth curriculum is an effective resource for increasing knowledge among youth about the harms associated with e-cigarette use. Further research is needed to evaluate whether the intervention is associated with behavioral outcomes over time.