Objectives: In an attempt to reduce tobacco use among adolescents in the USA, some health educators have created school-based tobacco education programmes. However, none currently exist for middle and high school educators. The current study sought to determine if middle and high school educators’ knowledge about combustible cigarettes and electronic cigarettes (e-cigarettes) improved following an educational session about youth tobacco use. Design: Pre-/post-assessment was employed to measure change in knowledge. Setting: Educators ( N = 41) from a rural, southern middle and high school were invited to take part in the study during an educational workshop held during an in-service training event. Method: In addition to seven knowledge questions, participants also provided demographic information and details of current and previous use of cigarettes and e-cigarettes. Chi-square analyses examined changes in responses to individual items, and total pre-/post-knowledge score change was compared using a dependent t-test. Independent t-tests examined differences between knowledge change and participants’ personal and behavioural characteristics. Results: Participants’ overall knowledge improved from pre- to the post-test ( p < .05); however, there was no relationship between pre-/post-test responses for individual items. In addition, there were no differences between participants’ knowledge change when compared by age, sex, grades taught and past use of cigarettes or e-cigarettes. Discussion: Increasing middle school and high school educators’ knowledge about tobacco products, particularly novel devices, is important due to the increasing rates of use among youth. More research is needed to determine how educators’ knowledge can help decrease tobacco initiation and use among school-aged children.