Production of the oxygen-derived free radicals in peritoneal lavage after one-hour hemorrhagic shock were investigated on a rat model. A statistically significant increased activity of superoxide dismutase (SOD), and an insignificant enhancement of concentration of -SH groups, comparing to the control animals was shown. There was no difference in the level of malondialdehyde (MDA) in the peritoneal fluid from the bled animals and the control group. The results indicate an increased antioxidative potential of the peritoneal content in the early phase of hemorrhagic shock.