PhDAims: To investigate the relationship between oral health and obesity in adolescents attending Public and Private Schools in Sharjah City, United Arab Emirates. Methods: 1094 adolescents attending secondary school in Sharjah City were asked to participate in a randomised cross-sectional study, (QMREC2007/60). Two separate structured questionnaires were used to determine; 1. The demographic details, dietary habits, physical activity and oral hygiene practice from the adolescents and 2. Socio-economic and general health from their guardian. A two part clinical examination i) dental caries (WHO, 1997) and oral cleanliness (Pitts et al., 1997), ii) measurement of height and weight to calculate BMI was also carried out. Data analysis included descriptive, univariate and multiple regressions. Results: Full dataset on 803 adolescents was obtained and used for analysis. The study response rate of 93% resulted in 50 % male, 40% UAE nationals and 66% attending Private school. The mean DMFT was 3.19 (SD 2.9), 25% were caries free, mean BMI was 21 and 15% were obese. A significant association between DMFT and BMI was found (r=0,097, p=0.006), with each extra 10 point in BMI there was a 0.57 increase in DMFT. The DMFT predictive model confirmed significant association of father’s education (p<0.001), gender (p=0.008) and ethnicity (p=0.001). Positive significance of age (p<0.001), consumption of tea with sugar (p=0.024) and soft drinks (p<0.001), whereas three daily meals (p=0.009) and visiting the dentist (p=0.007) were protective. The BMI model confirmed positive significance of age (p<0.001), school fees (p=0.005), obesity in family (p<0.001) and soft drink consumption (p<0.001). Three daily meals (p=0.007) and increased drinking frequency of milk (p=0.026) were found to be protective. Conclusions: Analysis of the final model suggests that there is no clear relationship between obesity and dental caries, but that the consumption of soft drinks was a leading predictor for both diseases (obesity and dental caries)