Aim: We aimed to investigate the levels and relationships of antioxidants, lipid peroxidation and leptin altogether in marasmic malnutrition. Method: Thirty marasmic children (age 14.4±10.3 months) and 28 control subjects were included. Erythrocyte superoxide dismutase (SOD) and catalase (CAT) activities, glutathione (GSH) level, and serum malondialdehyde (MDA) and leptin levels were measured. Result: Malnourished children had significantly lower erythrocyte SOD activity (1583±417 vs. 3403±1901 U/gHb, respectively, P<0.001), CAT activity (1139±92 vs. 1663±302 k/gHb, p<0.001), GSH level (25.9±5.4 vs. 48.1±17.0 μmol/gHb, p<0.001) and leptin levels (3.6±1.1 vs. 11.8±4.5 ng/mL, respectively, p<0.001), compared with control subjects. However mean MDA concentration of marasmic children (11.1±2.5 nmol/mL) was found to be significantly higher than that of the control subjects (6.6±3.9 nmol/mL) (p<0.001). Significant negative correlations were detected between CAT and MDA (r=-0.476, P=0.009), between SOD and MDA (r=-0.534, p=0.004), and GSH and MDA (r=-0.439, p=0.015) in marasmic children. No significant correlation was found between leptin and oxidation markers (p>0.05). Conclusion: Marasmic children had increased lipid peroxidation and decreased antioxidant enzyme activities and leptin. Lack of associations between leptin, anthropometric measurements and oxidative stress may be due to the excessive loss of adipose tissue and related very low levels of leptin in marasmic children.