So-called effective schools are characterised by properties such as a strong and purposeful school leadership and a favourable school ethos. In a previous study we showed that a school's degree of teacher-rated ethos was inversely associated with student gambling and risk gambling. Building on these findings, the current study aims to examine the associations that teachers' ratings of the school leadership share with gambling and risk gambling among students in the second grade of upper secondary school in Stockholm (age 17-18 years). Data were drawn from the Stockholm School Survey and the Stockholm Teacher Survey with information from 5191 students and 1061 teachers in 46 upper secondary schools. School-level information from administrative registers was also linked to the data. The statistical method was two-level binary logistic regression analysis. Teachers' average ratings of the school leadership were inversely associated with both gambling (OR 0.96, 95% CI 0.93-0.998, p = 0.039) and risk gambling (OR 0.94, 95% CI 0.89-0.99, p = 0.031) among upper secondary students, whilst adjusting for sociodemographic characteristics at the student and the school level. The findings lend further support to the hypothesis that characteristics of effective schools may reduce students' inclination to engage in gambling and risk gambling behaviours.