PURPOSE To investigate whether an association exists between obesity and optic nerve parameters. METHODS This was a prospective comparative study including 125 eyes of 63 obese and 122 eyes of 62 healthy pediatric subjects. Optic nerve measurements were performed using the Cirrus spectral domain optical coherence tomograph (SD-OCT). RESULTS The disc area, cup volume, mean and vertical C/D ratio, inferior and temporal RNFL thickness values were significantly higher in the control group than the obese group; however, age, sex, mean, superior and nasal RNFL thickness and rim area measurements were not statistically significantly different between the two groups. Age was significantly negatively correlated with temporal RNFL thickness in the obese group. Girls had significantly higher rim area, mean and superior RNFL thickness, and lower cup volume and vertical C/D ratio than boys in the obese group. CONCLUSION These results could be helpful in the diagnosis and follow-up of obese children.