Objective:To determine the dental caries experience and body mass index (BMI) of primary school children from both public and private schools in Ugbowo, Benin City. Materials and Methods: Primary school children from conveniently selected private and public schools were examined for dental caries and also underwent height and weight measurement for their BMI calculation during the Association of Resident Doctors, University of Benin Teaching Hospital School Health program in December 2010, using the WHO criteria. Results: Of the participants, 3.8% and 5.2% of them were overweight and obese respectively. A total of 33 (15.7%) of the children had dental caries with a mean decayed, missing filled, and teeth (DMFT) of 0.25 ± 0.04. The prevalence of untreated caries (decayed teeth [DT]), DMFT were 30 (14.3%), 1 (0.5%), and 2 (1.0%) respectively. DT contributed 90.9% (30/33) of DMFT that for the mean DMFT in underweight children was 0.21 that for the normal weight children were 0.26 that for the overweight children was 0.50 and for the obese children was 0.18. The prevalence of dental caries was the highest among obese participants followed by normal weight, underweight and overweight participants. There was no significant association between BMI, DMFT and caries experience. Conclusion: Dental caries experience among primary school children in Ugbowo is comparable to that reported in other Nigerian Pediatric populations and an increasing trend in the prevalence of overweight and obesity. However, non-significant association between the BMI and caries experience was noted. Success-oriented oral health promotion should take cognizance of differential prevalence of dental caries in terms of gender and type of school recorded in this study.