Introduction: Protein energy malnutrition (PEM) is one of the most important public health problems in many developing countries including India, South East Asia and Africa. It is a wide-spread deficiency disease among children of low socio-economic groups. Oxidative stress might plays an important role in conversion of marasmus to kwashiorkor. Aim: Hence the aim of this present study is to assess serum levels of micronutrients which directly plays an important role as antioxidants so that, the cause of oxidative stress can be identified. Materials and Methods: For this study total 54 children (both male and female) of age between 1-5 years who were suffering from different degrees of PEM were selected and grouped into Marasmus (n=31) and kwashiorkor (n= 23). 15 children who had no signs of PEM were selected as control group. In all the participants we measured plasma vitamin A, C, E plasma zinc, selenium and antioxidant enzyme Glutathione Peroxidase (GSH-Px) and its co-substrate Glutathione (GSH). Observation: though we observed lower levels of vitamin A, C, E in both groups of PEM when compared to control, very least levels were observed in kwashiorkor when compared between three groups (P<0.01). And the same lowest levels of GSH-Px and its co-substrate GSH in kwashiorkor was observed (p<0.01). Conclusion: from the above results we demonstrate that oxidative stress might plays as important role in conversion of marasmus to kwashiorkor.