To examine whether thermal injury alters the superoxide dismutase (SOD) concentrations in various types of tissue or plasma, we studied the plasma and tissue Mn- and Cu/Zn-SOD levels in a rodent burn model. The animals were resuscitated with saline (50 mg/kg, ip) immediately following thermal injury and thereafter were sacrificed at either 6 or 24 hours post-burn. The Mn- and Cu/Zn-SOD levels were measured using an enzyme-linked immunosorbent assay (ELISA). The plasma Mn- and Cu/Zn-SOD concentrations significantly increased 6 hours after the injury and positively correlated with the burn size. The kidney Mn-SOD concentrations were significantly higher 24 hours after the injury in the animals with 30% burns than in those with either sham or 50% burn injuries. The lung Cu/Zn-SOD concentrations were also significantly higher 6 hours after the injury in animals with 30% burns than in the other two types above. These findings suggest that the changes in the SOD concentrations after burn injury vary according to the type of SOD and also the type of tissue. As a result, the SOD concentrations may play some role in the early response to thermal trauma.