Objective: To assess the effectiveness of a dental health education program, ‘Smiles not Tears’ in preventing Early Childhood Caries in young Aboriginal children. Basic research design: Community trial. Clinical setting: Aboriginal Community Controlled Health Services in rural, remote and metropolitan areas in New South Wales, Australia. Participants: Aboriginal families who had a child six months of age. Interventions: Aboriginal Health Workers from eight Aboriginal Community Controlled Health Services in rural, remote and metropolitan areas in New South Wales recruited Aboriginal families with young children to participate in the Smiles not Tears dental education program. A convenience sample of Aboriginal children from the same communities was recruited to form a historical control group. Main outcome measures: The caries prevalence at 30 months of age compared to children of a similar age in the control group. Results: More children in the test group were caries free (n =104; 97.2%) when compared to the historical control group (n = 54; 65.9%). Only three children in the test group had caries which is less than the control group (n = 29). Conclusion: These results suggest that the Smiles not Tears dental education program has a positive impact on reducing the caries prevalence in young Aboriginal children. Keywords: Children, dental caries, health promotion, Indigenous, prevention