: Substance use (smoking, drinking and illicit drug use) remains, a serious problem for young people living in industrialised countries. There is increasing interest in interventions to modify the school, environment, addressing the multiple upstream determinants of young, people's health. This article provides an overview of current theory, about how secondary school environments influence young people's, substance use before focusing on the Theory of Human Functioning and, School Organisation. It critically examines the extent to which this, theory is substantiated by quantitative and qualitative evidence and, considers how the theory might be elaborated to better inform future, empirical research.<br/>