From the perspective of salutogenesis, schools have opportunities to create supportive environments for health and well-being, but there is a need for more knowledge about positive health determinants in the school setting. The aim of this study was to analyse adolescents’ self-reported positive health and its association with supportive factors in the school environment. Data was derived from a cross-sectional study in which pupils were aged 12–16 (n=1527). A positive health scale was used to examine the association of positive health with the following determinants: classroom participation; teacher support; peer support; parental support; and personal relative affluence. Data was analysed with multiple logistic regression. The results showed that positive health was associated with classroom participation and support from teachers and parents more commonly among boys than girls. All determinants were significantly associated with pupils’ positive health. The conclusion is that students’ positive health is strongly associated with support from the school. Classroom participation and support are major concerns for the health of pupils, and it is essential to develop these aspects of the school environment.