摘要:Introduction: Dental caries and obesity are multifactorial diseases with diet being a common contributory factor. Many studies have reported varied outcomes about the association between dental caries and body mass index. But, there is no published study that investigates this association among female students in Tehran. The main aim of this study was to examine the relationship between dental caries and body mass index (BMI) in a sample of female students in Tehran. Methods: In this cross-sectional study, 416 students aged between 10 to 12 years was examined for dental caries using WHO standard diagnostic criteria. The Decayed, missing and filled of permanent teeth (DMFT) were recorded. The student's weight and height were measured by two trained examiner and their BMI were calculated. BMI-for-age and dental caries categories were analyzed with Pearson correlation coefficient, Chi-square, and t-tests using SPSS computer software. Results: The mean DMFT score and BMI of the study population was 1.03 ± 1.41 and 18.11 ± 3.33 respectively. The findings showed that 58.9% of the children had a normal weight, 27.9% were overweight, 10.3% were obese, and only 2.9% of the students were thin when they were compared with WHO standard of BMI for children with the same age. The respective mean DMFT values for BMI groups (thin, normal, overweight and obese) were 1.25, 0.73, 1.42, and 1.65, respectively. There was a significant association ( P < 0.05) between dental caries and high BMI. Conclusions: This study demonstrated a significant association between caries frequency with high body mass index. For these reasons, the evaluation of nutritional status in students should be implemented in control programs for dental caries both on the community, schools, and individual levels.