Psychoactive substance use by students is common in many countries, obliging schools to deliver drug education. However, some jurisdictions do not prepare teachers for engaging their students in honest, knowledge-based education. This article looks at the history and queries the purposes of contemporary drug education. It compares current approaches to drug education with those of other "vice" issues addressed in the history of public schools, such as sex education and temperance education. It critically challenges the question of knowledge definition and production related to psychoactive substances. Finally, some of the theoretical groundings on which to base teacher education for drug education are considered.