Introduction and Objectives: Dental caries share risk factors with diet. The objective was to investigate the possible correlation between caries and BMI in children of the NGO "Pour un Sourire d'Enfant" in Cambodia. Material and methods: A cross-sectional study was conducted on 344 students of 6-18 years. The BMI-for-age was calculated using the WHO AnthroPlus Software v.1.0.4. Statistical analysis was with SPSS v.24 using ², Kruskal-Wallis and Mann-Whitney tests for univariate comparisons and correlation tests (Spearman, Kendall's tau and Pearson) for multivariate associations. Results: The mean DMFT was 5.83 ± 3.84 and 95% of the participants had experience of caries, especially at low ages (6-11 years). The majority (67%) had normal BMI-for-age, 25% underweight and 8% overweight. There was an inverse and significant correlation between dental caries and BMI-for-age, r (290) = -0.126, p = 0.032 (Pearson's coefficient). Discussion: Many researchers have already investigated this possible association, with results inconsistent mostly in populations from developed countries, but not in developing countries. Possible causes have risen in Cambodia due to double burden of malnutrition at low ages and the recent trend of increasing consumption of diets high in sugar. Clinical Implications: Need to monitor diet and caries in developing countries. Conclusion: There was an inverse, statistically significant association showing that the increase in BMI-for-age corresponds to a decline in the number of dental caries. The reduced weight will be related to more dental caries. Future longitudinal studies will help to clarify the causality in this type of population. Schlagwörter: DMFT, BMI-for-age, Cambodia, malnutrition, pediatric dentistry