The purpose of this study was to investigate the relationship between birth weight and appetite related hormones, insulin resistance, and antioxidant status in overweight children aged 9-10 years. Thirty-four healthy overweight children (18 boys, 16 girls) were evaluated with respect to anthropometric measurement, lipid profiles, leptin, ghrelin, glucose, insulin, C-peptide, lipid soluble vitamins, and antioxidant enzyme activities. I found that birth weight was negatively correlated with insulin resistance parameters, ghrelin, and coenzyme Q10 levels. There was a significant positive correlation between present BMI and leptin level, while a negative correlation was noted between the BMI and α-tocopherol and lycopene levels. When total subjects were classified into three groups by tertiles of birth weight, the lowest tertile of birth weight (LTB) group showed higher levels of fasting glucose, HOMA-IR, and ghrelin level than the highest tertile of birth weight (HTB) groups. On the other hand, HTB group showed an increased oxidative stress (decreased coenzyme Q10 level and catalase activity) compared to the LTB group. In conclusion, plasma ghrelin level might play an important role in accelerated growth in overweight children with LTB. Increased insulin resistance is present in overweight children with LTB, while decreased coenzyme Q10 and catalase activity in overweight children with HTB. These results suggest that birth weight might be an important factor for determination of treatment for obesity related complications in childhood obesity.