To comply with workplace legislation, New Zealand schools are required to have policies regarding tobacco smoking. Many schools also have policies to prevent tobacco use by students, including education programmes, cessation support and punishment for students found smoking. This paper investigated the associations between school policies and the prevalence of students' cigarette smoking. Furthermore, we investigated the association between school policy and students' tobacco purchasing behavior, knowledge of health effects from tobacco use and likelihood of influencing others not to smoke. Data were obtained from a self-report survey administered to 2658 New Zealand secondary school students and staff from 63 schools selected using a multi-stage sampling procedure. Components of school policy were not significantly associated with smoking outcomes, health knowledge or health behavior, and weakly related to a punishment emphasis and students advising others to not smoke. Similarly, weak associations were found between not advising others to not smoke and policies with a punishment emphasis as well as smoke-free environments. The results suggest that having a school tobacco policy was unrelated to the prevalence of tobacco use among students, tobacco purchasing behavior and knowledge of the negative health effects of tobacco.