Abstract This pilot study examined the efficacy of Peer Support Australia’s anti-bullying module for primary schools’. A quantitative questionnaire was used to survey 77 students from two primary schools (mean age 10.1 years) in the greater Sydney, Australia area. One school implemented the anti-bullying intervention module, Speaking Up, (intervention school) the other school did not (non-intervention school). Students completed a survey containing questions relating to bullying behaviours in their school. This questionnaire was developed from Peer Relations Assessment Questionnaire Students (PRAQ) devised by Rigby and Slee (1993). This study has provided further evidence to suggest intervention programs are effective in reducing bullying behaviours. It has quantified the assumptions made regarding the efficacy of Speaking Up as a module which reduces bullying behaviours which was the principal purpose of this study. The current study into the anti-bullying intervention module, Speaking Up, provided further evidence for the following: • students developed friendships across the year groups; • students were more inclusive of others; • students developed the skills to support target students; and • students developed the skills to report bullying behaviours. The anti-bullying intervention module, Speaking Up, was shown to: • reduce the incidence of bullying behaviours; • change attitudes towards bullying behaviours in the culture of the school; • provide greater awareness of the different types of bullying behaviours; • provide support for the longer term benefits of the intervention program. Peer Support Australia’s primary schools anti-bullying module, Speaking Up, is an effective intervention strategy supporting students to develop the skills, knowledge and attitudes necessary to make a positive contribution to the creation and maintenance of a safe school environment by reducing bullying behaviours. The findings of the current study make a contribution to research already undertaken in this area.