Schools are increasingly seen as promising environments for initiatives to prevent mental disorders and to protect and promote mental health. This pilot study examined whether a school-based resiliency programme, "Bounce Back," increased protective factors associated with resilience. Thirty-nine children aged 8-10 years (M = 9.17, SD = 0.58) from two schools in Melbourne, Australia, were allocated to the "Bounce Back" intervention (N = 17) or comparison (N = 22) group. Partial support for the effectiveness of the programme was found. Children's optimism and self-efficacy in the intervention group increased significantly with a large effect size from pre- to post-intervention. These changes were maintained at the 3-month follow-up; however, changes in perceived access to supportive relationships and emotional regulation were not detected. This pilot study represents an important step in the validation of one of the most widely used programmes in Australian schools, and provides some support for its continued use.