The thermal injury leads to increasing level of intracellular reactive oxygen specimen (ROS) reducing the antioxidant defense system. This pathway has been associated with endothelial and microvascular dysfunction and finally with multiple organ dysfunction (MOD). The purpose of this prospective, randomized clinical study was to determine the oxidant-antioxidant balance and investigate the effects of antioxidant therapy (cytoflavin) in burns patients with toxic and post-hypoxic encephalopathy. The study included 60 patients with thermal trauma and encephalopathy. Thirty patients received standard intensive therapy and cytoflavin intravenously in dose 10 ml/day 24 h after trauma during 5 days and 30 patients of the control group received standard intensive therapy for burns. Both groups exhibited a high lipid peroxydation (LPO) (malondialdehyde, conjugate trienes) and low levels of the antioxidant defense system, vitamins A and E on the second day after trauma. On the 14th day of treatment, the level of LPO (p<0,01) and total MOD (p<0,05) index were significantly lower and MMSE scores were higher (p<0,01) compared to the control group. In conclusion, cytoflavin, due to its systemic and metabolic effects, was effective in the treatment of post-hypoxic encephalopathy after the thermal injury.