Objective: To assess the relationship between pediatric otitis media with effusion (OME) and body mass index (BMI). Methods: We assessed 140 children aged 2-7 years who underwent unilateral or bilateral ventilation tube insertion for treatment of OME (experimental group) and 190 children with no history of OME who underwent operations for conditions other than ear diseases during the same period. Each group was divided into four subgroups based on BMI by age and gender: underweight (BMI below normal limits; BMIp5th percentile), normal (BMI within normal limits; 5thoBMIo85th percentile), overweight (BMI over normal limits; 85thpBMIo95th percentile) and obese ( BMIX95th percentile). We explored differences in BMI, and serum triglycerides (TG) and total cholesterol (TC), between the experimental and control group, in comparison with values from those of standard body weight. Results: The prevalence of obesity was significantly higher in the experimental than in the control group (Po0.05). BMI, TG and TC did not, however, differ significantly between groups, according to standard body weight. Conclusion: Pediatric obesity may have an effect on the development of OME, but pediatric overweight may be not associated with occurrence of OME.