The WHO health promoting school (HPS) approach covers key areas including school-based programmes improving students' psychological health, but there have been few studies evaluating the resilience performance of these schools. This study compared the resilience scores between schools within the healthy school award (HSA) scheme (HPS group) and those not (non-HPS group). We conducted a cross-sectional survey of grade-one students (aged 12), all teachers and parents of mainstream secondary schools recruited by stratified random sampling in one large Territory of Hong Kong using validated resilience questionnaires during November-December 2005. Four non-HPS and four HPS secondary schools were recruited, respectively, involving 1408 students, 891 parents and 91 teachers, with similar baseline characteristics. The HPS students were found to have better scores than non-HPS students (average age 12.4 year-old in both groups) in all dimensions with significantly higher scores in 'Peer Support' (p = 0.013), 'Making a Difference' (p = 0.011), 'About Me' (p = 0.027) and 'Generally Happy' (p = 0.011). There was no difference in the scores between non-HPS and HPS parents. The HPS teachers reported significantly higher scores in 'Health Policies' (p = 0.023), 'Social Environment' (p = 0.049), 'School Community Relations' (p = 0.048), 'Personal Skills Building' (p = 0.008) and 'Partnership & Health Services' (p = 0.047). The secondary HPS students and teachers reported significantly higher resilience scores than those of non-HPS. This study shows that the HSA scheme under WHO has the potential to exert positive changes in students and teachers and the concept of HPS is effective in building resilience among major school stakeholders.