Burn trauma leads to increased production of reactive oxygen species and compromises the antioxidant systems. The aim of present study was to assess the total antioxidant capacity of plasma (TAC) in burn patients and evaluate its usefulness in clinical practice through analysis of association between TAC and indices of patient prognosis. We investigated TAC in 48 adults and 27 children with severe burn trauma and in 26 healthy controls. TAC was measured on the admission and every week thereafter until discharge or death of patients. The prognosis of the patients was evaluated by the Baux Index and the Abbreviated Burn Severity Index (ABSI). TAC was significantly decreased in both groups with burn trauma as compared with the controls and the decrease was a long lasting event. Significant indirect negative correlation was found between BSAB and TAC values measured in the later phase of injury. In adults an indirect correlation was found between ABSI and the lowest TAC measured on the 7th day or later. Correlations between TAC values and Baux Index were absent both in adults and in children.