Background: Workplace safety and health is a major public health concern, but largely absent from the school health curriculum. Little is known about teachers' perceptions of teaching workplace safety and health topics. Methods: We administered a 41-item questionnaire reflecting the theory of planned behavior, modified to measure knowledge, to 242 middle and high school teachers in career and technical education and academic subjects. We conducted confirmatory factor analysis to assess the measures' psychometric properties and factorial ANOVAs to compare differences among participants' knowledge, attitude toward, self-efficacy, and intention (to teach) workplace safety and health by sex, prior work injury, and main subject taught. Results: Confirmatory factor analyses indicated the measures reflected the theory. Factorial ANOVAs suggested female teachers had statistically significantly lower mean self-efficacy scores than did male teachers to teach workplace safety and health. Male occupational career and technical education teachers demonstrated higher mean knowledge scores than male teachers in other subjects. Participants not injured at work had higher knowledge scores than those who had been injured. Conclusion: Self-efficacy (influenced by sex) and knowledge (influenced by subject taught and previous workplace injury) revealed factors that may affect teachers' provision of workplace safety and health education, a critical yet overlooked component of school health.