Background: Aboriginal preschool children across Canada are at increased risk for Early Childhood Caries (ECC) when compared with their non-Aboriginal age cohorts. Current research indicates that dental public health programs fail to prevent ECC because intervention often arrives too late. Objectives: To evaluate the effectiveness of the dental hygiene-coordinated prenatal nutrition program, delivered by community-based nutrition educators on First Nations reserves located in the Sioux Lookout Zone (Northwestern Ontario) on: (1) parents/caregivers’ beliefs and behavioural decisions related to dental preventive practices and feeding habits of young children; (2) oral health status and treatment needs of those children; (3) early childhood obesity. Methods: Cross-sectional oral health surveys of Anishnaabe 2–5 year olds conducted in 2001and 2002 in 16 communities; 8 communities classified as “high” intervention and 8 as “low” intervention based on frequency of contact and content of contact between nutrition educators and prenatal women. Trained and calibrated dental hygienists examined children for dental caries and oral hygiene and measured height and weight. A questionnaire was used to assess caregiver knowledge, beliefs, and practices in relation to the oral health of the child. Results: 471 (72% response) and 705 (65% response) caregiver-and-child pairs participated in 2001 and 2002, respectively. Oral health knowledge in this population was high and significantly higher among caregivers in the high-intervention communities. In high-intervention communities, caregivers brushed children’s teeth more frequently and started at an earlier age. Differences in feeding habits were noted with regard to bottle feeding on child’s demand and the sugar-rich content of the bottle. Children in high-intervention communities required dental treatment under general anesthetic (GA) but at a later age, were less likely to have abscessed teeth and had less untreated decay by age 4 than those in the low-intervention communities. The program also had significant positive effects on the child’s oral hygiene and body mass index (BMI). Conclusion: The prenatal nutrition program improved caregivers’ knowledge of ECC. However, factors that place undo strain on the caregiver and lead to poor oral hygiene and dietary habits among children in Aboriginal communities need to be addressed. Some strategies to confront these factors are discussed in the paper.