Aims: The School Health and Alcohol Harm Reduction Project (SHAHRP study) aimed to reduce alcohol-related harm in secondary school students. Design: The study adopted a quasi-experimental research design, incorporating randomly selected and allocated intervention and control groups and measured change at eight, 20 and 32 month follow-ups. Setting: Metropolitan, government secondary schools in Perth, Western Australia. Participants: The sample involved over 2300 students. The retention rate was seventy six approximately (75.9%) over 32 months. Intervention: The evidence-based intervention was a curriculum program, with an explicit harm minimisation goal and was conducted in two phases over a two year period. Measures: Measures of change included: knowledge, attitude, consumption, context of use, harm associated with own use and harm associated with other peoples use of alcohol. Findings: Significant knowledge and attitude effects occurred early in the study and were maintained to final follow-up, however, scores were starting to converge by 32 months. There was an impact on consumption during the program delivery phase with intervention students consuming 31.4% and 31.7% less alcohol, and 25.2% and 33.8% less likely to consumed to harmful/hazardous levels. The program had no impact on context of alcohol use. The program was effective in impacting on the harm that young people experience associated with their own use of alcohol, with intervention students experiencing 32.7%, 16.7% and 22.9% less harm from first follow-up onwards. There was little program impact on the harm that students experienced associated with other peoples use of alcohol. Conclusions: The results of this study support two distinct areas for the future of alcohol education programs in schools: the adoption of a harm reduction goal and the fundamental use of classroom intervention to achieve change.