AIM: To determine which primary prevention measures work, which do not work and why. METHOD: A systematic literature search identified trials investigating the effectiveness of primary interventions on problem gambling. INCLUSION CRITERIA: Randomised and quasi- randomised controlled trials. Excluded was any primary, general practice or outpatient care for problem or pathological gambling related issues. RESULTS: 13 studies were included in this review. Interventions were: Video only; Lectures and activities; Video plus lectures and activities; Educational programs; Warning messages; Self-help workbook and a motivational interview. 7/9 studies found positive impact on gambling attitudes/misconceptions. 6/7 studies showed a positive impact on gambling knowledge. Narrative reports indicate that gambling behaviour could be influenced through education, warning messages, and work books. Two studies report that positive impacts from interventions that aimed to improve coping and problem resolution skills. CONCLUSIONS: Interventions should be implemented to students aged 12 to 14 in Years 7 and 8. Interventions should be school-based and psycho-educational. The most effective and efficient way to administer the intervention is in the form of a video, activity and lecture combination. Appropriately trained personnel are needed for implementation.