US adolescents experience a higher rate of largely preventable job-related injuries compared with adults. Safety education is considered critical to the prevention of these incidents. This study evaluates the effectiveness of a foundational curriculum from the National Institute for Occupational Safety and Health (NIOSH), Talking Safety, to change adolescents' workplace safety and health knowledge, attitude, subjective norm, self-efficacy, and behavioral intention to engage in workplace safety actions. The study also examines the impact of teacher fidelity of curriculum implementation on student outcomes. A multilevel evaluation, based on a modified theory of planned behavior, was conducted in 2016 with 1748 eighth-graders in Miami-Dade, Florida. Post-intervention, students had statistically significant increases (p < .05) in mean scores across outcomes: workplace safety knowledge (34%), attitude (5%), subjective norm (7%), selfefficacy (7%), and behavioral intention (7%). Consistent with theory, gains in attitude (b = 0.25, p < .001), subjective norm (b = 0.07, p < .01), and self-efficacy (b = 0.55, p < .001) were associated with gains in behavioral intention. Higher levels of implementation fidelity were associated with significant gains across outcome measures: knowledge (b = 0.60, p < .