Malnutrition as a lack of several substances containing antioxidants such as vitamins and micronutrients, while showing a predisposition for lipid peroxidation and DNA damage, is also characterized by a slowing down of the metabolic processes, which may then have protective properties against DNA damage due to a reduction in endogenous free radical production. This study aimed to examine the oxidative status and DNA damage in cases of marasmus. The study comprised 28 infants aged 624 months with marasmus only and 28 age-matched healthy infants. DNA damage was examined by the alkali single cell electrophoresis method (Comet assay) on mononuclear leukocytes. The total oxidant status (TOS) and total antioxidant status (TAS) were measured by colormetric auto-analyzer and the oxidative stress index (OSI) was calculated. The TOS, TAS, and OSI levels of the patient group were found to be significantly lower compared to the control group (P < 0.01, P < 0.01, P < 0.01, respectively). No statistically significant difference was found between the two groups in terms of mononuclear leukocyte DNA damage (P > 0.05). The findings of this study showed that in marasmus cases, the oxidative and antioxidative processes, which have a counteractive effect, decreased together. The other results of the study indicate that there is no increase in DNA damage in marasmus cases. J. Clin. Lab. Anal. 26:161-166, 2012. (c) 2012 Wiley Periodicals, Inc.