Dental caries and obesity are both multifactorial disease with a complex etiology and both are associated with dietary habits. Prevalence of dental caries and an association between body mass index (BMI) and dental caries among school children The present was done on 1500 school going children to assess the prevalence of dental caries in 12-15 year old overweight children. Weight and height were measured in light clothing and without shoes using an electronic weighing scale. Subjects’ heights were measured using a stadiometre. Subjects were examined on an upright chair in adequate natural daylight and dental caries was measured by using DMF index. Chi-square test was used to analyze and compare qualitative data whereas unpaired ‘t’ test was used to analyze and compare quantative data Amongst 1500 children, 156 were found to be overweight, 443 were normal weight. When mean BMI between overweight and normal weight were compared a highly significant difference was observed. When DMFT of overweight and normal weight were compared no significant difference was observed Dental caries was observed more in females as compared to males and no significant difference was observed between dental caries and weight gain