AIM The present study assessed caries experience in an adolescent population being treated for severe obesity. The DMFT indices of a group of obese adolescents (n = 41) and a group of nonobese adolescents (n = 41) were compared. DESIGN The parameters examined in this transversal study were body mass index (BMI) and the number of decayed, missing, and filled teeth (DMFT). The obese and nonobese groups were matched by age, gender, and parental socio-occupational category. Differences between the two groups were assessed using nonparametric tests. RESULTS There was a significant association between BMI and DMFT indices (P = 0.01) in the severely obese group. The obese adolescents were more likely to have caries than the nonobese ones. CONCLUSIONS The severely obese children (n = 16) had a high level of caries experience. Given the tremendous increase in the prevalence of obesity in children, dentists should promote a healthy diet not only to prevent dental decay but also to reduce the risk for obesity. Dentists should participate in multidisciplinary medical teams managing obese adolescents.